diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 35853c6..d278be3 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -2,9 +2,13 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="org.y20k.trackbook">
 
+    <!-- EXCLUDE NON-GPS DEVICES -->
+    <uses-feature android:name="android.hardware.location.gps" android:required="true" />
+
     <!-- NORMAL PERMISSIONS, automatically granted -->
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
     <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
+    <uses-permission android:name="android.permission.VIBRATE"/>
     <uses-permission android:name="android.permission.INTERNET" />
 
     <!-- DANGEROUS PERMISSIONS, must request -->
diff --git a/app/src/main/java/org/y20k/trackbook/MainActivity.java b/app/src/main/java/org/y20k/trackbook/MainActivity.java
index 3eecb80..abbcf9d 100644
--- a/app/src/main/java/org/y20k/trackbook/MainActivity.java
+++ b/app/src/main/java/org/y20k/trackbook/MainActivity.java
@@ -29,6 +29,7 @@ import android.location.Location;
 import android.os.Build;
 import android.os.Bundle;
 import android.os.Environment;
+import android.os.Vibrator;
 import android.preference.PreferenceManager;
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
@@ -42,6 +43,7 @@ import android.support.v4.app.FragmentPagerAdapter;
 import android.support.v4.content.ContextCompat;
 import android.support.v4.content.LocalBroadcastManager;
 import android.support.v7.app.AppCompatActivity;
+import android.support.v7.app.AppCompatDelegate;
 import android.support.v7.widget.CardView;
 import android.util.SparseArray;
 import android.view.MenuItem;
@@ -53,6 +55,7 @@ import android.widget.Toast;
 import org.osmdroid.config.Configuration;
 import org.y20k.trackbook.helpers.DialogHelper;
 import org.y20k.trackbook.helpers.LogHelper;
+import org.y20k.trackbook.helpers.NightModeHelper;
 import org.y20k.trackbook.helpers.TrackbookKeys;
 import org.y20k.trackbook.layout.NonSwipeableViewPager;
 
@@ -91,6 +94,12 @@ public class MainActivity extends AppCompatActivity implements TrackbookKeys {
     private int mSelectedTab;
 
 
+    /* Sets day / night mode */
+    static {
+        AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_FOLLOW_SYSTEM);
+    }
+
+
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
@@ -447,6 +456,14 @@ public class MainActivity extends AppCompatActivity implements TrackbookKeys {
                 mainActivityMapFragment.handleShowMyLocation();
             }
         });
+        mFloatingActionButtonLocation.setOnLongClickListener(new View.OnLongClickListener() {
+            @Override
+            public boolean onLongClick(View v) {
+                longPressFeedback(R.string.toastmessage_long_press_night_mode_switch);
+                NightModeHelper.switchToOpposite(MainActivity.this);
+                return true;
+            }
+        });
     }
 
 
@@ -608,6 +625,18 @@ public class MainActivity extends AppCompatActivity implements TrackbookKeys {
     }
 
 
+    /* Inform user and give haptic feedback (vibration) */
+    private void longPressFeedback(int stringResource) {
+        // inform user
+        Toast.makeText(this, stringResource, Toast.LENGTH_LONG).show();
+        // vibrate 50 milliseconds
+        Vibrator v = (Vibrator) getSystemService(Context.VIBRATOR_SERVICE);
+        v.vibrate(50);
+//            v.vibrate(VibrationEffect.createOneShot(50, DEFAULT_AMPLITUDE)); // todo check if there is a support library vibrator
+    }
+
+
+
     /* Check which permissions have been granted */
     private List<String> checkPermissions() {
         List<String> permissions = new ArrayList<>();
diff --git a/app/src/main/java/org/y20k/trackbook/MainActivityTrackFragment.java b/app/src/main/java/org/y20k/trackbook/MainActivityTrackFragment.java
index 64d56ca..47ff56e 100644
--- a/app/src/main/java/org/y20k/trackbook/MainActivityTrackFragment.java
+++ b/app/src/main/java/org/y20k/trackbook/MainActivityTrackFragment.java
@@ -467,12 +467,12 @@ public class MainActivityTrackFragment extends Fragment implements AdapterView.O
                     case BottomSheetBehavior.STATE_EXPANDED:
                         // statistics sheet expanded
                         mTrackManagementLayout.setVisibility(View.INVISIBLE);
-                        mStatisticsSheet.setBackgroundColor(ContextCompat.getColor(mActivity, R.color.trackbook_white_85percent));
+                        mStatisticsSheet.setBackgroundColor(ContextCompat.getColor(mActivity, R.color.statistic_sheet_background_expanded));
                         break;
                     case BottomSheetBehavior.STATE_COLLAPSED:
                         // statistics sheet collapsed
                         mTrackManagementLayout.setVisibility(View.VISIBLE);
-                        mStatisticsSheet.setBackgroundColor(ContextCompat.getColor(mActivity, R.color.trackbook_white));
+                        mStatisticsSheet.setBackgroundColor(ContextCompat.getColor(mActivity, R.color.statistic_sheet_background_collapsed));
                         mStatisticsSheetBehavior.setState(BottomSheetBehavior.STATE_COLLAPSED);
                         break;
                     case BottomSheetBehavior.STATE_HIDDEN:
@@ -492,9 +492,9 @@ public class MainActivityTrackFragment extends Fragment implements AdapterView.O
                     mTrackManagementLayout.setVisibility(View.INVISIBLE);
                 }
                 if (slideOffset < 0.125f) {
-                    mStatisticsSheet.setBackgroundColor(ContextCompat.getColor(mActivity, R.color.trackbook_white));
+                    mStatisticsSheet.setBackgroundColor(ContextCompat.getColor(mActivity, R.color.statistic_sheet_background_collapsed));
                 } else {
-                    mStatisticsSheet.setBackgroundColor(ContextCompat.getColor(mActivity, R.color.trackbook_white_85percent));
+                    mStatisticsSheet.setBackgroundColor(ContextCompat.getColor(mActivity, R.color.statistic_sheet_background_expanded));
                 }
             }
         };
diff --git a/app/src/main/java/org/y20k/trackbook/helpers/NightModeHelper.java b/app/src/main/java/org/y20k/trackbook/helpers/NightModeHelper.java
new file mode 100644
index 0000000..2e6c462
--- /dev/null
+++ b/app/src/main/java/org/y20k/trackbook/helpers/NightModeHelper.java
@@ -0,0 +1,127 @@
+/**
+ * NightModeHelper.java
+ * Implements the NightModeHelper class
+ * A NightModeHelper can toggle and restore the state of the theme's Night Mode
+ *
+ * This file is part of
+ * TRACKBOOK - Movement Recorder for Android
+ *
+ * Copyright (c) 2016-18 - Y20K.org
+ * Licensed under the MIT-License
+ * http://opensource.org/licenses/MIT
+ *
+ * Trackbook uses osmdroid - OpenStreetMap-Tools for Android
+ * https://github.com/osmdroid/osmdroid
+ */
+
+package org.y20k.trackbook.helpers;
+
+import android.app.Activity;
+import android.content.Context;
+import android.content.SharedPreferences;
+import android.content.res.Configuration;
+import android.os.Build;
+import android.preference.PreferenceManager;
+import android.support.v7.app.AppCompatDelegate;
+import android.view.View;
+
+
+/**
+ * NightModeHelper class
+ */
+public final class NightModeHelper implements TrackbookKeys {
+
+
+    /* Define log tag */
+    private static final String LOG_TAG = NightModeHelper.class.getSimpleName();
+
+
+    /* Switches to opposite theme */
+    public static void switchToOpposite(Activity activity) {
+        switch (getCurrentNightModeState(activity)) {
+            case Configuration.UI_MODE_NIGHT_NO:
+                // night mode is currently not active - turn on night mode
+                activateNightMode(activity);
+                break;
+            case Configuration.UI_MODE_NIGHT_YES:
+                // night mode is currently active - turn off night mode
+                deactivateNightMode(activity);
+                break;
+            case Configuration.UI_MODE_NIGHT_UNDEFINED:
+                // don't know what mode is active - turn off night mode
+                deactivateNightMode(activity);
+                break;
+        }
+        activity.recreate(); // todo check if necessary
+    }
+
+
+    /* Sets night mode / dark theme */
+    public static void restoreSavedState(Activity activity) {
+        int savedNightModeState = loadNightModeState(activity);
+        int currentNightModeState = getCurrentNightModeState(activity);
+        LogHelper.i(LOG_TAG, "Saved state of Night Mode = " + savedNightModeState + " || current state of Night Mode = " + currentNightModeState + " || NO=16 & YES=32"); // todo remove
+        if (savedNightModeState != -1 && savedNightModeState != currentNightModeState) {
+//            switch (savedNightModeState) {
+//                case Configuration.UI_MODE_NIGHT_NO:
+//                     // turn off night mode
+//                    deactivateNightMode(activity);
+//                    break;
+//                case Configuration.UI_MODE_NIGHT_YES:
+//                    // turn on night mode
+//                    activateNightMode(activity);
+//                    break;
+//                case Configuration.UI_MODE_NIGHT_UNDEFINED:
+//                    // turn off night mode
+//                    deactivateNightMode(activity);
+//                    break;
+//            }
+//            activity.recreate(); // todo check if necessary
+        }
+    }
+
+
+    /* Returns state of night mode */
+    private static int getCurrentNightModeState(Context context) {
+        return context.getResources().getConfiguration().uiMode & Configuration.UI_MODE_NIGHT_MASK;
+    }
+
+
+    /* Activates Night Mode */
+    private static void activateNightMode(Activity activity) {
+        AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_YES);
+        View decorView = activity.getWindow().getDecorView();
+        decorView.setSystemUiVisibility(0);
+        saveNightModeState(activity, Configuration.UI_MODE_NIGHT_NO);
+    }
+
+
+    /* Deactivates Night Mode */
+    private static void deactivateNightMode(Activity activity) {
+        AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_NO);
+        View decorView = activity.getWindow().getDecorView();
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
+            decorView.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LIGHT_STATUS_BAR);
+        } else {
+            decorView.setSystemUiVisibility(0);
+        }
+        saveNightModeState(activity, Configuration.UI_MODE_NIGHT_YES);
+    }
+
+
+    /* Save state of night mode */
+    private static void saveNightModeState(Context context, int currentState) {
+        SharedPreferences settings = PreferenceManager.getDefaultSharedPreferences(context);
+        SharedPreferences.Editor editor = settings.edit();
+        editor.putInt(PREF_NIGHT_MODE_STATE, currentState);
+        editor.apply();
+    }
+
+
+    /* Load state of Night Mode */
+    private static int loadNightModeState(Context context) {
+        return PreferenceManager.getDefaultSharedPreferences(context).getInt(PREF_NIGHT_MODE_STATE, -1);
+    }
+
+}
+
diff --git a/app/src/main/java/org/y20k/trackbook/helpers/TrackbookKeys.java b/app/src/main/java/org/y20k/trackbook/helpers/TrackbookKeys.java
index c2e694a..81663cc 100644
--- a/app/src/main/java/org/y20k/trackbook/helpers/TrackbookKeys.java
+++ b/app/src/main/java/org/y20k/trackbook/helpers/TrackbookKeys.java
@@ -51,6 +51,7 @@ public interface TrackbookKeys {
     String PREFS_FAB_STATE = "fabStatePrefs";
     String PREFS_TRACKER_SERVICE_RUNNING = "trackerServiceRunning";
     String PREFS_CURRENT_TRACK_DURATION = "currentTrackDuration";
+    String PREF_NIGHT_MODE_STATE = "prefNightModeState";
 
     /* INSTANCE STATE */
     String INSTANCE_FIRST_START = "firstStart";
diff --git a/app/src/main/res/drawable/ic_delete_forever_grey_24dp.xml b/app/src/main/res/drawable/ic_delete_forever_24dp.xml
similarity index 88%
rename from app/src/main/res/drawable/ic_delete_forever_grey_24dp.xml
rename to app/src/main/res/drawable/ic_delete_forever_24dp.xml
index 57b27aa..d61792d 100644
--- a/app/src/main/res/drawable/ic_delete_forever_grey_24dp.xml
+++ b/app/src/main/res/drawable/ic_delete_forever_24dp.xml
@@ -5,5 +5,5 @@
         android:viewportHeight="24.0">
     <path
         android:pathData="M6,19c0,1.1 0.9,2 2,2h8c1.1,0 2,-0.9 2,-2L18,7L6,7v12zM8.46,11.88l1.41,-1.41L12,12.59l2.12,-2.12 1.41,1.41L13.41,14l2.12,2.12 -1.41,1.41L12,15.41l-2.12,2.12 -1.41,-1.41L10.59,14l-2.13,-2.12zM15.5,4l-1,-1h-5l-1,1L5,4v2h14L19,4z"
-        android:fillColor="@color/trackbook_grey" />
+        android:fillColor="@color/track_management_icons" />
 </vector>
diff --git a/app/src/main/res/drawable/ic_delete_forever_white_24dp.xml b/app/src/main/res/drawable/ic_delete_forever_white_24dp.xml
deleted file mode 100644
index e96a47c..0000000
--- a/app/src/main/res/drawable/ic_delete_forever_white_24dp.xml
+++ /dev/null
@@ -1,9 +0,0 @@
-<vector xmlns:android="http://schemas.android.com/apk/res/android"
-        android:width="24dp"
-        android:height="24dp"
-        android:viewportWidth="24.0"
-        android:viewportHeight="24.0">
-    <path
-        android:pathData="M6,19c0,1.1 0.9,2 2,2h8c1.1,0 2,-0.9 2,-2L18,7L6,7v12zM8.46,11.88l1.41,-1.41L12,12.59l2.12,-2.12 1.41,1.41L13.41,14l2.12,2.12 -1.41,1.41L12,15.41l-2.12,2.12 -1.41,-1.41L10.59,14l-2.13,-2.12zM15.5,4l-1,-1h-5l-1,1L5,4v2h14L19,4z"
-        android:fillColor="@color/trackbook_white" />
-</vector>
diff --git a/app/src/main/res/drawable/ic_export_white_24dp.xml b/app/src/main/res/drawable/ic_export_white_24dp.xml
deleted file mode 100644
index f82a153..0000000
--- a/app/src/main/res/drawable/ic_export_white_24dp.xml
+++ /dev/null
@@ -1,9 +0,0 @@
-<vector xmlns:android="http://schemas.android.com/apk/res/android"
-        android:width="24dp"
-        android:height="24dp"
-        android:viewportWidth="24.0"
-        android:viewportHeight="24.0">
-    <path
-        android:pathData="M9,3L5,6.99h3L8,14h2L10,6.99h3L9,3zM16,17.01L16,10h-2v7.01h-3L15,21l4,-3.99h-3z"
-        android:fillColor="@color/trackbook_white" />
-</vector>
\ No newline at end of file
diff --git a/app/src/main/res/drawable/ic_file_download_white_24dp.xml b/app/src/main/res/drawable/ic_file_download_24dp.xml
similarity index 82%
rename from app/src/main/res/drawable/ic_file_download_white_24dp.xml
rename to app/src/main/res/drawable/ic_file_download_24dp.xml
index 3e6cb05..2ac4629 100644
--- a/app/src/main/res/drawable/ic_file_download_white_24dp.xml
+++ b/app/src/main/res/drawable/ic_file_download_24dp.xml
@@ -5,5 +5,5 @@
         android:viewportHeight="24.0">
     <path
         android:pathData="M19,9h-4V3H9v6H5l7,7 7,-7zM5,18v2h14v-2H5z"
-        android:fillColor="@color/trackbook_white" />
+        android:fillColor="@color/track_management_icons" />
 </vector>
diff --git a/app/src/main/res/drawable/ic_file_download_grey_24dp.xml b/app/src/main/res/drawable/ic_file_download_grey_24dp.xml
deleted file mode 100644
index 1e5bf77..0000000
--- a/app/src/main/res/drawable/ic_file_download_grey_24dp.xml
+++ /dev/null
@@ -1,9 +0,0 @@
-<vector xmlns:android="http://schemas.android.com/apk/res/android"
-        android:width="24dp"
-        android:height="24dp"
-        android:viewportWidth="24.0"
-        android:viewportHeight="24.0">
-    <path
-        android:pathData="M19,9h-4V3H9v6H5l7,7 7,-7zM5,18v2h14v-2H5z"
-        android:fillColor="@color/trackbook_grey" />
-</vector>
diff --git a/app/src/main/res/drawable/ic_info_grey_24dp.xml b/app/src/main/res/drawable/ic_info_24dp.xml
similarity index 86%
rename from app/src/main/res/drawable/ic_info_grey_24dp.xml
rename to app/src/main/res/drawable/ic_info_24dp.xml
index b49c82e..b701d0e 100644
--- a/app/src/main/res/drawable/ic_info_grey_24dp.xml
+++ b/app/src/main/res/drawable/ic_info_24dp.xml
@@ -4,6 +4,6 @@
         android:viewportWidth="24.0"
         android:viewportHeight="24.0">
     <path
-        android:fillColor="@color/trackbook_grey"
-        android:pathData="M11,17h2v-6h-2v6zM12,2C6.48,2 2,6.48 2,12s4.48,10 10,10 10,-4.48 10,-10S17.52,2 12,2zM12,20c-4.41,0 -8,-3.59 -8,-8s3.59,-8 8,-8 8,3.59 8,8 -3.59,8 -8,8zM11,9h2L13,7h-2v2z"/>
+        android:pathData="M11,17h2v-6h-2v6zM12,2C6.48,2 2,6.48 2,12s4.48,10 10,10 10,-4.48 10,-10S17.52,2 12,2zM12,20c-4.41,0 -8,-3.59 -8,-8s3.59,-8 8,-8 8,3.59 8,8 -3.59,8 -8,8zM11,9h2L13,7h-2v2z"
+        android:fillColor="@color/statistic_sheet_icons" />
 </vector>
diff --git a/app/src/main/res/drawable/ic_info_white_24dp.xml b/app/src/main/res/drawable/ic_info_white_24dp.xml
deleted file mode 100644
index de69530..0000000
--- a/app/src/main/res/drawable/ic_info_white_24dp.xml
+++ /dev/null
@@ -1,9 +0,0 @@
-<vector xmlns:android="http://schemas.android.com/apk/res/android"
-        android:width="24dp"
-        android:height="24dp"
-        android:viewportWidth="24.0"
-        android:viewportHeight="24.0">
-    <path
-        android:fillColor="@color/trackbook_white"
-        android:pathData="M12,2C6.48,2 2,6.48 2,12s4.48,10 10,10 10,-4.48 10,-10S17.52,2 12,2zM13,17h-2v-6h2v6zM13,9h-2L11,7h2v2z"/>
-</vector>
diff --git a/app/src/main/res/drawable/ic_my_location_grey_24dp.xml b/app/src/main/res/drawable/ic_my_location_24dp.xml
similarity index 91%
rename from app/src/main/res/drawable/ic_my_location_grey_24dp.xml
rename to app/src/main/res/drawable/ic_my_location_24dp.xml
index 28aacd1..79d5816 100644
--- a/app/src/main/res/drawable/ic_my_location_grey_24dp.xml
+++ b/app/src/main/res/drawable/ic_my_location_24dp.xml
@@ -4,6 +4,6 @@
         android:viewportWidth="24.0"
         android:viewportHeight="24.0">
     <path
-        android:fillColor="@color/trackbook_grey"
+        android:fillColor="@color/location_buttom_icon"
         android:pathData="M12,8c-2.21,0 -4,1.79 -4,4s1.79,4 4,4 4,-1.79 4,-4 -1.79,-4 -4,-4zM20.94,11c-0.46,-4.17 -3.77,-7.48 -7.94,-7.94L13,1h-2v2.06C6.83,3.52 3.52,6.83 3.06,11L1,11v2h2.06c0.46,4.17 3.77,7.48 7.94,7.94L11,23h2v-2.06c4.17,-0.46 7.48,-3.77 7.94,-7.94L23,13v-2h-2.06zM12,19c-3.87,0 -7,-3.13 -7,-7s3.13,-7 7,-7 7,3.13 7,7 -3.13,7 -7,7z"/>
 </vector>
diff --git a/app/src/main/res/drawable/ic_track_calendar_white_24dp.xml b/app/src/main/res/drawable/ic_track_calendar_white_24dp.xml
deleted file mode 100644
index 0cc338b..0000000
--- a/app/src/main/res/drawable/ic_track_calendar_white_24dp.xml
+++ /dev/null
@@ -1,9 +0,0 @@
-<vector xmlns:android="http://schemas.android.com/apk/res/android"
-        android:width="24dp"
-        android:height="24dp"
-        android:viewportWidth="24.0"
-        android:viewportHeight="24.0">
-    <path
-        android:fillColor="@color/trackbook_white"
-        android:pathData="M9,11L7,11v2h2v-2zM13,11h-2v2h2v-2zM17,11h-2v2h2v-2zM19,4h-1L18,2h-2v2L8,4L8,2L6,2v2L5,4c-1.11,0 -1.99,0.9 -1.99,2L3,20c0,1.1 0.89,2 2,2h14c1.1,0 2,-0.9 2,-2L21,6c0,-1.1 -0.9,-2 -2,-2zM19,20L5,20L5,9h14v11z"/>
-</vector>
diff --git a/app/src/main/res/layout/activity_main.xml b/app/src/main/res/layout/activity_main.xml
index f1ab3c9..a93b03f 100644
--- a/app/src/main/res/layout/activity_main.xml
+++ b/app/src/main/res/layout/activity_main.xml
@@ -23,12 +23,12 @@
             android:clickable="true"
             android:focusable="true"
             android:contentDescription="@string/descr_fab_my_location"
-            app:backgroundTint="@color/trackbook_white"
+            app:backgroundTint="@color/location_buttom_background"
             app:fabSize="mini"
             app:layout_constraintBottom_toBottomOf="@+id/fabMainButton"
             app:layout_constraintStart_toStartOf="parent"
             app:layout_constraintTop_toTopOf="@+id/fabMainButton"
-            app:srcCompat="@drawable/ic_my_location_grey_24dp" />
+            app:srcCompat="@drawable/ic_my_location_24dp" />
 
 
         <!-- BUTTON SAVE AND CLEAR -->
@@ -56,7 +56,7 @@
             android:clickable="true"
             android:focusable="true"
             android:contentDescription="@string/descr_fab_sub_menu_label_1"
-            app:cardBackgroundColor="@color/trackbook_white"
+            app:cardBackgroundColor="@color/fab_button_card_background"
             app:cardCornerRadius="4dp"
             app:cardElevation="4dp"
             app:cardUseCompatPadding="true"
@@ -72,7 +72,8 @@
                 android:paddingRight="6dp"
                 android:paddingTop="2dp"
                 android:text="@string/fab_sub_menu_save"
-                android:textAppearance="?android:attr/textAppearanceSmall"
+                android:textAppearance="@style/TextAppearance.AppCompat.Small"
+                android:textColor="@color/fab_button_card_text"
                 android:textStyle="bold"
                 tools:layout_editor_absoluteX="110dp"
                 tools:layout_editor_absoluteY="239dp" />
@@ -103,7 +104,7 @@
             android:clickable="true"
             android:focusable="true"
             android:contentDescription="@string/descr_fab_sub_menu_label_2"
-            app:cardBackgroundColor="@color/trackbook_white"
+            app:cardBackgroundColor="@color/fab_button_card_background"
             app:cardCornerRadius="4dp"
             app:cardElevation="4dp"
             app:cardUseCompatPadding="true"
@@ -119,7 +120,8 @@
                 android:paddingRight="6dp"
                 android:paddingTop="2dp"
                 android:text="@string/fab_sub_menu_clear"
-                android:textAppearance="?android:attr/textAppearanceSmall"
+                android:textAppearance="@style/TextAppearance.AppCompat.Small"
+                android:textColor="@color/fab_button_card_text"
                 android:textStyle="bold"
                 tools:layout_editor_absoluteX="124dp"
                 tools:layout_editor_absoluteY="447dp" />
@@ -148,7 +150,7 @@
             android:id="@+id/navigation"
             android:layout_width="0dp"
             android:layout_height="wrap_content"
-            android:background="@color/trackbook_red"
+            android:background="@color/bottom_navigation_background"
             android:clickable="true"
             android:focusable="true"
             app:itemIconTint="@drawable/selector_bottom_navigation"
diff --git a/app/src/main/res/layout/custom_dropdown_item_collapsed.xml b/app/src/main/res/layout/custom_dropdown_item_collapsed.xml
index 759026b..7fd0097 100644
--- a/app/src/main/res/layout/custom_dropdown_item_collapsed.xml
+++ b/app/src/main/res/layout/custom_dropdown_item_collapsed.xml
@@ -7,6 +7,7 @@
     android:paddingBottom="@dimen/activity_vertical_margin"
     android:paddingStart="@dimen/activity_horizontal_margin"
     android:paddingEnd="@dimen/activity_horizontal_margin"
-    android:textColor="@color/trackbook_grey"
+    android:textColor="@color/track_management_text"
+    android:background="@color/track_management_background"
     android:ellipsize="marquee"
     android:singleLine="true" />
\ No newline at end of file
diff --git a/app/src/main/res/layout/custom_dropdown_item_expanded.xml b/app/src/main/res/layout/custom_dropdown_item_expanded.xml
index f1d4db5..7fd0097 100644
--- a/app/src/main/res/layout/custom_dropdown_item_expanded.xml
+++ b/app/src/main/res/layout/custom_dropdown_item_expanded.xml
@@ -7,7 +7,7 @@
     android:paddingBottom="@dimen/activity_vertical_margin"
     android:paddingStart="@dimen/activity_horizontal_margin"
     android:paddingEnd="@dimen/activity_horizontal_margin"
-    android:textColor="@color/trackbook_grey"
-    android:background="@color/trackbook_white"
+    android:textColor="@color/track_management_text"
+    android:background="@color/track_management_background"
     android:ellipsize="marquee"
     android:singleLine="true" />
\ No newline at end of file
diff --git a/app/src/main/res/layout/fragment_main_track.xml b/app/src/main/res/layout/fragment_main_track.xml
index 01a8307..d7ca6ed 100644
--- a/app/src/main/res/layout/fragment_main_track.xml
+++ b/app/src/main/res/layout/fragment_main_track.xml
@@ -34,7 +34,7 @@
         android:layout_width="@dimen/bottom_sheet_width"
         android:layout_height="match_parent"
         android:layout_gravity="center_horizontal"
-        android:background="@color/trackbook_white"
+        android:background="@color/statistic_sheet_background_expanded"
         app:behavior_hideable="false"
         app:behavior_peekHeight="54dp"
         app:layout_behavior="android.support.design.widget.BottomSheetBehavior">
diff --git a/app/src/main/res/layout/fragment_main_track_management.xml b/app/src/main/res/layout/fragment_main_track_management.xml
index 9e6085c..5024680 100644
--- a/app/src/main/res/layout/fragment_main_track_management.xml
+++ b/app/src/main/res/layout/fragment_main_track_management.xml
@@ -5,7 +5,7 @@
     android:layout_width="@dimen/bottom_sheet_width"
     android:layout_height="wrap_content"
     android:layout_centerHorizontal="true"
-    android:background="@color/trackbook_white">
+    android:background="@color/track_management_background">
 
     <Spinner
         android:id="@+id/track_selector"
@@ -31,7 +31,7 @@
         app:layout_constraintBottom_toBottomOf="@+id/track_selector"
         app:layout_constraintEnd_toStartOf="@+id/delete_button"
         app:layout_constraintTop_toTopOf="@+id/track_selector"
-        app:srcCompat="@drawable/ic_file_download_grey_24dp" />
+        app:srcCompat="@drawable/ic_file_download_24dp" />
 
     <ImageButton
         android:id="@+id/delete_button"
@@ -43,6 +43,6 @@
         app:layout_constraintBottom_toBottomOf="@+id/export_button"
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintTop_toTopOf="@+id/export_button"
-        app:srcCompat="@drawable/ic_delete_forever_grey_24dp" />
+        app:srcCompat="@drawable/ic_delete_forever_24dp" />
 
 </android.support.constraint.ConstraintLayout>
\ No newline at end of file
diff --git a/app/src/main/res/layout/fragment_main_track_statistics.xml b/app/src/main/res/layout/fragment_main_track_statistics.xml
index f5a35e2..2a5fa2e 100644
--- a/app/src/main/res/layout/fragment_main_track_statistics.xml
+++ b/app/src/main/res/layout/fragment_main_track_statistics.xml
@@ -22,6 +22,7 @@
         android:text="@string/statistics_sheet_h1_statistics"
         android:textAllCaps="true"
         android:textAppearance="@android:style/TextAppearance.Medium"
+        android:textColor="@color/statistic_sheet_text"
         android:textStyle="bold"
         app:layout_constraintEnd_toStartOf="@+id/statistics_icon"
         app:layout_constraintStart_toStartOf="parent"
@@ -37,7 +38,7 @@
         app:layout_constraintBottom_toBottomOf="@+id/statistics_headline"
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintTop_toTopOf="@+id/statistics_headline"
-        app:srcCompat="@drawable/ic_info_grey_24dp" />
+        app:srcCompat="@drawable/ic_info_24dp" />
 
     <TextView
         android:id="@+id/statistics_p_distance"
@@ -46,7 +47,8 @@
         android:layout_marginTop="24dp"
         android:contentDescription="@string/descr_statistics_sheet_p_distance"
         android:text="@string/statistics_sheet_p_distance"
-        android:textAppearance="@android:style/TextAppearance.Material.Small"
+        android:textAppearance="@style/TextAppearance.AppCompat.Small"
+        android:textColor="@color/statistic_sheet_text"
         app:layout_constraintStart_toStartOf="@+id/statistics_headline"
         app:layout_constraintTop_toBottomOf="@+id/statistics_headline" />
 
@@ -57,7 +59,8 @@
         android:layout_marginStart="16dp"
         android:contentDescription="@string/descr_statistics_sheet_p_distance_value"
         android:text="@string/statistics_sheet_p_default_data"
-        android:textAppearance="@android:style/TextAppearance.Material.Medium"
+        android:textAppearance="@style/TextAppearance.AppCompat.Medium"
+        android:textColor="@color/statistic_sheet_text"
         app:layout_constraintBottom_toBottomOf="@+id/statistics_p_distance"
         app:layout_constraintStart_toEndOf="@+id/statistics_p_distance"
         app:layout_constraintTop_toTopOf="@+id/statistics_p_distance" />
@@ -68,6 +71,8 @@
         android:layout_height="wrap_content"
         android:layout_marginTop="16dp"
         android:contentDescription="@string/descr_statistics_sheet_p_steps"
+        android:textAppearance="@style/TextAppearance.AppCompat.Small"
+        android:textColor="@color/statistic_sheet_text"
         android:text="@string/statistics_sheet_p_steps"
         app:layout_constraintStart_toStartOf="@+id/statistics_p_distance"
         app:layout_constraintTop_toBottomOf="@+id/statistics_p_distance" />
@@ -79,7 +84,8 @@
         android:layout_marginStart="16dp"
         android:contentDescription="@string/descr_statistics_sheet_p_steps_value"
         android:text="@string/statistics_sheet_p_default_data"
-        android:textAppearance="@android:style/TextAppearance.Material.Medium"
+        android:textAppearance="@style/TextAppearance.AppCompat.Medium"
+        android:textColor="@color/statistic_sheet_text"
         app:layout_constraintBottom_toBottomOf="@+id/statistics_p_steps"
         app:layout_constraintStart_toEndOf="@+id/statistics_p_steps"
         app:layout_constraintTop_toTopOf="@+id/statistics_p_steps" />
@@ -90,6 +96,8 @@
         android:layout_height="0dp"
         android:layout_marginTop="16dp"
         android:contentDescription="@string/descr_statistics_sheet_p_waypoints"
+        android:textAppearance="@style/TextAppearance.AppCompat.Small"
+        android:textColor="@color/statistic_sheet_text"
         android:text="@string/statistics_sheet_p_waypoints"
         app:layout_constraintStart_toStartOf="@+id/statistics_p_steps"
         app:layout_constraintTop_toBottomOf="@+id/statistics_p_steps" />
@@ -101,7 +109,8 @@
         android:layout_marginStart="16dp"
         android:contentDescription="@string/descr_statistics_sheet_p_waypoints_value"
         android:text="@string/statistics_sheet_p_default_data"
-        android:textAppearance="@android:style/TextAppearance.Material.Medium"
+        android:textAppearance="@style/TextAppearance.AppCompat.Medium"
+        android:textColor="@color/statistic_sheet_text"
         app:layout_constraintBottom_toBottomOf="@+id/statistics_p_waypoints"
         app:layout_constraintStart_toEndOf="@+id/statistics_p_waypoints"
         app:layout_constraintTop_toTopOf="@+id/statistics_p_waypoints" />
@@ -112,6 +121,8 @@
         android:layout_height="wrap_content"
         android:layout_marginTop="16dp"
         android:contentDescription="@string/descr_statistics_sheet_p_duration"
+        android:textAppearance="@style/TextAppearance.AppCompat.Small"
+        android:textColor="@color/statistic_sheet_text"
         android:text="@string/statistics_sheet_p_duration"
         app:layout_constraintStart_toStartOf="@+id/statistics_p_waypoints"
         app:layout_constraintTop_toBottomOf="@+id/statistics_p_waypoints" />
@@ -123,7 +134,8 @@
         android:layout_marginStart="16dp"
         android:contentDescription="@string/descr_statistics_sheet_p_duration_value"
         android:text="@string/statistics_sheet_p_default_data"
-        android:textAppearance="@android:style/TextAppearance.Material.Medium"
+        android:textAppearance="@style/TextAppearance.AppCompat.Medium"
+        android:textColor="@color/statistic_sheet_text"
         app:layout_constraintBottom_toBottomOf="@+id/statistics_p_duration"
         app:layout_constraintStart_toEndOf="@+id/statistics_p_duration"
         app:layout_constraintTop_toTopOf="@+id/statistics_p_duration" />
@@ -134,6 +146,8 @@
         android:layout_height="wrap_content"
         android:layout_marginTop="16dp"
         android:contentDescription="@string/descr_statistics_sheet_p_recording_start"
+        android:textAppearance="@style/TextAppearance.AppCompat.Small"
+        android:textColor="@color/statistic_sheet_text"
         android:text="@string/statistics_sheet_p_recording_start"
         app:layout_constraintStart_toStartOf="@+id/statistics_p_duration"
         app:layout_constraintTop_toBottomOf="@+id/statistics_p_duration" />
@@ -145,7 +159,8 @@
         android:layout_marginStart="16dp"
         android:contentDescription="@string/descr_statistics_sheet_p_recording_start_value"
         android:text="@string/statistics_sheet_p_default_data"
-        android:textAppearance="@android:style/TextAppearance.Material.Medium"
+        android:textAppearance="@style/TextAppearance.AppCompat.Medium"
+        android:textColor="@color/statistic_sheet_text"
         app:layout_constraintBottom_toBottomOf="@+id/statistics_p_recording_start"
         app:layout_constraintStart_toEndOf="@+id/statistics_p_recording_start"
         app:layout_constraintTop_toTopOf="@+id/statistics_p_recording_start" />
@@ -156,6 +171,8 @@
         android:layout_height="wrap_content"
         android:layout_marginTop="16dp"
         android:contentDescription="@string/descr_statistics_sheet_p_recording_end"
+        android:textAppearance="@style/TextAppearance.AppCompat.Small"
+        android:textColor="@color/statistic_sheet_text"
         android:text="@string/statistics_sheet_p_recording_stop"
         app:layout_constraintStart_toStartOf="@+id/statistics_p_recording_start"
         app:layout_constraintTop_toBottomOf="@+id/statistics_p_recording_start" />
@@ -167,7 +184,8 @@
         android:layout_marginStart="16dp"
         android:contentDescription="@string/descr_statistics_sheet_p_recording_end_value"
         android:text="@string/statistics_sheet_p_default_data"
-        android:textAppearance="@android:style/TextAppearance.Material.Medium"
+        android:textAppearance="@style/TextAppearance.AppCompat.Medium"
+        android:textColor="@color/statistic_sheet_text"
         app:layout_constraintBottom_toBottomOf="@+id/statistics_p_recording_stop"
         app:layout_constraintStart_toEndOf="@+id/statistics_p_recording_stop"
         app:layout_constraintTop_toTopOf="@+id/statistics_p_recording_stop" />
@@ -178,6 +196,8 @@
         android:layout_height="wrap_content"
         android:layout_marginTop="16dp"
         android:contentDescription="@string/descr_statistics_sheet_p_positive_elevation"
+        android:textAppearance="@style/TextAppearance.AppCompat.Small"
+        android:textColor="@color/statistic_sheet_text"
         android:text="@string/statistics_sheet_p_positive_elevation"
         app:layout_constraintStart_toStartOf="@+id/statistics_p_recording_stop"
         app:layout_constraintTop_toBottomOf="@+id/statistics_p_recording_stop" />
@@ -187,8 +207,9 @@
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_marginStart="16dp"
+        android:textAppearance="@style/TextAppearance.AppCompat.Medium"
+        android:textColor="@color/statistic_sheet_text"
         android:text="@string/statistics_sheet_p_default_data"
-        android:textAppearance="@android:style/TextAppearance.Material.Medium"
         app:layout_constraintBottom_toBottomOf="@+id/statistics_p_positive_elevation"
         app:layout_constraintStart_toEndOf="@+id/statistics_p_positive_elevation"
         app:layout_constraintTop_toTopOf="@+id/statistics_p_positive_elevation" />
@@ -199,6 +220,8 @@
         android:layout_height="wrap_content"
         android:layout_marginTop="16dp"
         android:contentDescription="@string/descr_statistics_sheet_p_negative_elevation"
+        android:textAppearance="@style/TextAppearance.AppCompat.Small"
+        android:textColor="@color/statistic_sheet_text"
         android:text="@string/statistics_sheet_p_negative_elevation"
         app:layout_constraintStart_toStartOf="@+id/statistics_p_positive_elevation"
         app:layout_constraintTop_toBottomOf="@+id/statistics_p_positive_elevation" />
@@ -208,8 +231,9 @@
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_marginStart="16dp"
+        android:textAppearance="@style/TextAppearance.AppCompat.Medium"
+        android:textColor="@color/statistic_sheet_text"
         android:text="@string/statistics_sheet_p_default_data"
-        android:textAppearance="@android:style/TextAppearance.Material.Medium"
         app:layout_constraintBottom_toBottomOf="@+id/statistics_p_negative_elevation"
         app:layout_constraintStart_toEndOf="@+id/statistics_p_negative_elevation"
         app:layout_constraintTop_toTopOf="@+id/statistics_p_negative_elevation" />
@@ -220,6 +244,8 @@
         android:layout_height="wrap_content"
         android:layout_marginTop="16dp"
         android:contentDescription="@string/descr_statistics_sheet_p_max_altitude"
+        android:textAppearance="@style/TextAppearance.AppCompat.Small"
+        android:textColor="@color/statistic_sheet_text"
         android:text="@string/statistics_sheet_p_max_altitude"
         app:layout_constraintStart_toStartOf="@+id/statistics_p_negative_elevation"
         app:layout_constraintTop_toBottomOf="@+id/statistics_p_negative_elevation" />
@@ -229,8 +255,9 @@
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_marginStart="16dp"
+        android:textAppearance="@style/TextAppearance.AppCompat.Medium"
+        android:textColor="@color/statistic_sheet_text"
         android:text="@string/statistics_sheet_p_default_data"
-        android:textAppearance="@android:style/TextAppearance.Material.Medium"
         app:layout_constraintBottom_toBottomOf="@+id/statistics_p_max_altitude"
         app:layout_constraintStart_toEndOf="@+id/statistics_p_max_altitude"
         app:layout_constraintTop_toTopOf="@+id/statistics_p_max_altitude" />
@@ -242,6 +269,8 @@
         android:layout_marginBottom="16dp"
         android:layout_marginTop="16dp"
         android:contentDescription="@string/descr_statistics_sheet_p_min_altitude"
+        android:textAppearance="@style/TextAppearance.AppCompat.Small"
+        android:textColor="@color/statistic_sheet_text"
         android:text="@string/statistics_sheet_p_min_altitude"
         app:layout_constraintBottom_toBottomOf="parent"
         app:layout_constraintStart_toStartOf="@+id/statistics_p_max_altitude"
@@ -252,8 +281,9 @@
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_marginStart="16dp"
+        android:textAppearance="@style/TextAppearance.AppCompat.Medium"
+        android:textColor="@color/statistic_sheet_text"
         android:text="@string/statistics_sheet_p_default_data"
-        android:textAppearance="@android:style/TextAppearance.Material.Medium"
         app:layout_constraintBottom_toBottomOf="@+id/statistics_p_min_altitude"
         app:layout_constraintStart_toEndOf="@+id/statistics_p_min_altitude"
         app:layout_constraintTop_toTopOf="@+id/statistics_p_min_altitude" />
diff --git a/app/src/main/res/values-de/strings.xml b/app/src/main/res/values-de/strings.xml
index b2722fd..ec1d41c 100644
--- a/app/src/main/res/values-de/strings.xml
+++ b/app/src/main/res/values-de/strings.xml
@@ -53,6 +53,7 @@
     <string name="toast_message_export_success">GPX-Export erfolgreich:</string>
     <string name="toast_message_export_fail">GPX-Export fehlgeschlagen:</string>
     <string name="toast_message_elevation_info">Hinweis: Die Genauogkeit der Höhenmeter-Werte ist geräteabhängig. Gemessen werden die Steigungen und Gefälle der Gesamtstrecke.</string>
+    <string name="toastmessage_long_press_night_mode_switch">Schalter für Nachtmodus (Längeres Drücken erkannt)</string>
 
     <!-- map markers -->
     <string name="marker_description_source">Quelle</string>
diff --git a/app/src/main/res/values-id/strings.xml b/app/src/main/res/values-id/strings.xml
index 1d84eb2..e0a71dd 100644
--- a/app/src/main/res/values-id/strings.xml
+++ b/app/src/main/res/values-id/strings.xml
@@ -53,6 +53,7 @@
     <string name="toast_message_export_success">GPX export successful:</string>
     <string name="toast_message_export_fail">GPX export failed:</string>
     <string name="toast_message_elevation_info">Hint: The accuracy of elevation data depends on your device. The uphill and downhill elevation of the whole route is measured.</string>
+    <string name="toastmessage_long_press_night_mode_switch">Night mode switch (long press detected)</string>
 
     <!-- map markers -->
     <string name="marker_description_source">Source</string>
diff --git a/app/src/main/res/values-it/strings.xml b/app/src/main/res/values-it/strings.xml
index 6a7e81f..580bba5 100644
--- a/app/src/main/res/values-it/strings.xml
+++ b/app/src/main/res/values-it/strings.xml
@@ -53,6 +53,7 @@
     <string name="toast_message_export_success">L\'esportazione GPX è riuscita:</string>
     <string name="toast_message_export_fail">L\'esportazione GPX non è riuscita:</string>
     <string name="toast_message_elevation_info">Hint: The accuracy of elevation data depends on your device. The uphill and downhill elevation of the whole route is measured.</string>
+    <string name="toastmessage_long_press_night_mode_switch">Night mode switch (long press detected)</string>
 
     <!-- map markers -->
     <string name="marker_description_source">Fonte</string>
diff --git a/app/src/main/res/values-ja/strings.xml b/app/src/main/res/values-ja/strings.xml
index a2ab07f..2858d0e 100644
--- a/app/src/main/res/values-ja/strings.xml
+++ b/app/src/main/res/values-ja/strings.xml
@@ -53,6 +53,7 @@
     <string name="toast_message_export_success">GPX のエクスポートが完了しました:</string>
     <string name="toast_message_export_fail">GPX のエクスポートに失敗しました:</string>
     <string name="toast_message_elevation_info">ヒント: 標高データの精度は、お使いのデバイスによって異なります。ルート全体の上り坂と下り坂の標高を測定します。</string>
+    <string name="toastmessage_long_press_night_mode_switch">Night mode switch (long press detected)</string>
 
     <!-- map markers -->
     <string name="marker_description_source">ソース</string>
diff --git a/app/src/main/res/values-nb-rNO/strings.xml b/app/src/main/res/values-nb-rNO/strings.xml
index a4894be..04c41fc 100644
--- a/app/src/main/res/values-nb-rNO/strings.xml
+++ b/app/src/main/res/values-nb-rNO/strings.xml
@@ -53,6 +53,7 @@
     <string name="toast_message_export_success">GPX-eksportering vellykket:</string>
     <string name="toast_message_export_fail">GPX-eksportering mislyktes:</string>
     <string name="toast_message_elevation_info">Hint: Høydedataens nøyaktighet avhenger av enheten din. Opp og ned-stigningen for hele ruten måles.</string>
+    <string name="toastmessage_long_press_night_mode_switch">Night mode switch (long press detected)</string>
 
     <!-- map markers -->
     <string name="marker_description_source">Kilde</string>
diff --git a/app/src/main/res/values-night-v23/styles.xml b/app/src/main/res/values-night-v23/styles.xml
new file mode 100644
index 0000000..75f2741
--- /dev/null
+++ b/app/src/main/res/values-night-v23/styles.xml
@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+
+    <!-- Base application theme. -->
+    <style name="TrackbookAppTheme" parent="Theme.AppCompat.DayNight.NoActionBar">
+
+        <!-- Set AppCompat’s colors -->
+        <item name="colorPrimary">@color/trackbook_red</item>
+        <item name="colorPrimaryDark">@color/trackbook_white</item>
+        <item name="colorAccent">@color/trackbook_blue</item>
+
+        <!-- Don't show white status bar -->
+        <item name="android:windowLightStatusBar">false</item>
+        <item name="android:statusBarColor">@color/status_bar_background</item>
+
+    </style>
+
+    <!-- Drop down theme -->
+    <style name="TrackbookAppTheme.PopupOverlay" parent="Theme.AppCompat.DayNight.NoActionBar">
+        <item name="android:colorControlNormal">@color/track_management_text</item>
+        <item name="android:popupBackground">@color/track_management_background</item>
+    </style>
+
+</resources>
diff --git a/app/src/main/res/values-night/colors.xml b/app/src/main/res/values-night/colors.xml
new file mode 100644
index 0000000..e605cd5
--- /dev/null
+++ b/app/src/main/res/values-night/colors.xml
@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+
+    <!-- DAY THEME COLORS -->
+    <color name="status_bar_background">@color/trackbook_black</color>
+    <color name="bottom_navigation_background">@color/trackbook_black</color>
+
+    <color name="fab_button_card_text">@color/trackbook_white</color>
+    <color name="fab_button_card_background">@color/trackbook_grey_dark</color>
+
+    <color name="location_buttom_icon">@color/trackbook_white</color>
+    <color name="location_buttom_background">@color/trackbook_grey_dark</color>
+
+    <color name="track_management_text">@color/trackbook_white</color>
+    <color name="track_management_icons">@color/trackbook_white</color>
+    <color name="track_management_background">@color/trackbook_black</color>
+
+    <color name="statistic_sheet_text">@color/trackbook_white</color>
+    <color name="statistic_sheet_icons">@color/trackbook_white</color>
+    <color name="statistic_sheet_background_expanded">@color/trackbook_black_85percent</color>
+    <color name="statistic_sheet_background_collapsed">@color/trackbook_black</color>
+
+</resources>
diff --git a/app/src/main/res/values-nl/strings.xml b/app/src/main/res/values-nl/strings.xml
index 41728fa..6cf909f 100644
--- a/app/src/main/res/values-nl/strings.xml
+++ b/app/src/main/res/values-nl/strings.xml
@@ -53,6 +53,7 @@
     <string name="toast_message_export_success">GPX export successful:</string>
     <string name="toast_message_export_fail">GPX export failed:</string>
     <string name="toast_message_elevation_info">Hint: The accuracy of elevation data depends on your device. The uphill and downhill elevation of the whole route is measured.</string>
+    <string name="toastmessage_long_press_night_mode_switch">Night mode switch (long press detected)</string>
 
     <!-- map markers -->
     <string name="marker_description_source">Bron</string>
diff --git a/app/src/main/res/values-v23/styles.xml b/app/src/main/res/values-v23/styles.xml
index 0335113..48833b1 100644
--- a/app/src/main/res/values-v23/styles.xml
+++ b/app/src/main/res/values-v23/styles.xml
@@ -2,28 +2,23 @@
 <resources>
 
     <!-- Base application theme. -->
-    <style name="TrackbookAppTheme" parent="Theme.AppCompat.Light.NoActionBar">
+    <style name="TrackbookAppTheme" parent="Theme.AppCompat.DayNight.NoActionBar">
 
         <!-- Set AppCompat’s colors -->
         <item name="colorPrimary">@color/trackbook_red</item>
-        <item name="colorPrimaryDark">@color/trackbook_white</item>
+        <item name="colorPrimaryDark">@color/trackbook_red_dark</item>
         <item name="colorAccent">@color/trackbook_blue</item>
 
         <!-- Show white status bar -->
         <item name="android:windowLightStatusBar">true</item>
+        <item name="android:statusBarColor">@color/status_bar_background</item>
 
     </style>
 
-    <!--<style name="TrackbookAppTheme.NoActionBar">-->
-    <!--<item name="windowActionBar">false</item>-->
-    <!--<item name="windowNoTitle">true</item>-->
-    <!--</style>-->
-
-    <!--<style name="TrackbookAppTheme.AppBarOverlay" parent="ThemeOverlay.AppCompat.Dark.ActionBar" />-->
 
     <!-- Drop down theme -->
-    <style name="TrackbookAppTheme.PopupOverlay" parent="Theme.AppCompat.Light.NoActionBar">
-        <item name="android:colorControlNormal">@color/trackbook_grey</item>
+    <style name="TrackbookAppTheme.PopupOverlay" parent="Theme.AppCompat.DayNight.NoActionBar">
+        <item name="android:colorControlNormal">@color/track_management_text</item>
     </style>
 
 </resources>
diff --git a/app/src/main/res/values/colors.xml b/app/src/main/res/values/colors.xml
index 735b5eb..aa74a60 100644
--- a/app/src/main/res/values/colors.xml
+++ b/app/src/main/res/values/colors.xml
@@ -1,6 +1,27 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
 
+    <!-- DAY THEME COLORS -->
+    <color name="status_bar_background">@color/trackbook_white</color>
+    <color name="bottom_navigation_background">@color/trackbook_red</color>
+
+    <color name="fab_button_card_text">@color/trackbook_grey_dark</color>
+    <color name="fab_button_card_background">@color/trackbook_white</color>
+
+    <color name="location_buttom_icon">@color/trackbook_grey</color>
+    <color name="location_buttom_background">@color/trackbook_white</color>
+
+    <color name="track_management_text">@color/trackbook_grey_dark</color>
+    <color name="track_management_icons">@color/trackbook_grey_dark</color>
+    <color name="track_management_background">@color/trackbook_white</color>
+
+    <color name="statistic_sheet_text">@color/trackbook_grey_dark</color>
+    <color name="statistic_sheet_icons">@color/trackbook_grey_dark</color>
+    <color name="statistic_sheet_background_expanded">@color/trackbook_white_85percent</color>
+    <color name="statistic_sheet_background_collapsed">@color/trackbook_white</color>
+
+
+    <!-- COLOR NAMES -->
     <color name="trackbook_red">#FFD93025</color>
     <color name="trackbook_red_dark">#FFB31412</color>
     <color name="trackbook_red_85percent">#D9D93025</color>
@@ -16,6 +37,7 @@
     <color name="trackbook_white">#FFFFFFFF</color>
     <color name="trackbook_white_85percent">#D9FFFFFF</color>
     <color name="trackbook_black">#FF000000</color>
+    <color name="trackbook_black_85percent">#D9000000</color>
 
     <color name="trackbook_grey_lighter">#FFD2D6DA</color>
     <color name="trackbook_grey_light">#FFBDC1C6</color>
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index a225894..2c653fa 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -53,6 +53,7 @@
     <string name="toast_message_export_success">GPX export successful:</string>
     <string name="toast_message_export_fail">GPX export failed:</string>
     <string name="toast_message_elevation_info">Hint: The accuracy of elevation data depends on your device. The uphill and downhill elevation of the whole route is measured.</string>
+    <string name="toastmessage_long_press_night_mode_switch">Night mode switch (long press detected)</string>
 
     <!-- map markers -->
     <string name="marker_description_source">Source</string>
diff --git a/app/src/main/res/values/styles.xml b/app/src/main/res/values/styles.xml
index d0d375b..e44f5f3 100644
--- a/app/src/main/res/values/styles.xml
+++ b/app/src/main/res/values/styles.xml
@@ -2,25 +2,18 @@
 <resources>
 
     <!-- Base application theme. -->
-    <style name="TrackbookAppTheme" parent="Theme.AppCompat.Light.NoActionBar">
+    <style name="TrackbookAppTheme" parent="Theme.AppCompat.DayNight.NoActionBar">
 
         <!-- Set AppCompat’s colors -->
         <item name="colorPrimary">@color/trackbook_red</item>
-        <item name="colorPrimaryDark">@color/trackbook_grey_darker</item>
+        <item name="colorPrimaryDark">@color/trackbook_grey_dark</item>
         <item name="colorAccent">@color/trackbook_blue</item>
 
     </style>
 
-    <!--<style name="TrackbookAppTheme.NoActionBar">-->
-    <!--<item name="windowActionBar">false</item>-->
-    <!--<item name="windowNoTitle">true</item>-->
-    <!--</style>-->
-
-    <!--<style name="TrackbookAppTheme.AppBarOverlay" parent="ThemeOverlay.AppCompat.Dark.ActionBar" />-->
-
     <!-- Drop down theme -->
-    <style name="TrackbookAppTheme.PopupOverlay" parent="Theme.AppCompat.Light.NoActionBar">
-        <item name="android:colorControlNormal">@color/trackbook_grey</item>
+    <style name="TrackbookAppTheme.PopupOverlay" parent="Theme.AppCompat.DayNight.NoActionBar">
+        <item name="android:colorControlNormal">@color/track_management_text</item>
     </style>
 
 </resources>