diff --git a/app/src/main/java/com/cringe_studios/cringe_authenticator/fragment/SettingsFragment.java b/app/src/main/java/com/cringe_studios/cringe_authenticator/fragment/SettingsFragment.java
index ef9f7f7..4d1f50a 100644
--- a/app/src/main/java/com/cringe_studios/cringe_authenticator/fragment/SettingsFragment.java
+++ b/app/src/main/java/com/cringe_studios/cringe_authenticator/fragment/SettingsFragment.java
@@ -24,6 +24,7 @@ import com.cringe_studios.cringe_authenticator.crypto.Crypto;
 import com.cringe_studios.cringe_authenticator.crypto.CryptoException;
 import com.cringe_studios.cringe_authenticator.crypto.CryptoParameters;
 import com.cringe_studios.cringe_authenticator.databinding.FragmentSettingsBinding;
+import com.cringe_studios.cringe_authenticator.util.Appearance;
 import com.cringe_studios.cringe_authenticator.util.BiometricUtil;
 import com.cringe_studios.cringe_authenticator.util.DialogUtil;
 import com.cringe_studios.cringe_authenticator.util.FabUtil;
@@ -177,6 +178,27 @@ public class SettingsFragment extends NamedFragment {
             public void onNothingSelected(AdapterView<?> parent) {}
         });
 
+        String[] appearanceNames = new String[Appearance.values().length];
+        for(int i = 0; i < Appearance.values().length; i++) {
+            appearanceNames[i] = getResources().getString(Appearance.values()[i].getName());
+        }
+
+        binding.settingsAppearance.setAdapter(new ArrayAdapter<>(requireContext(), android.R.layout.simple_list_item_1, appearanceNames));
+        binding.settingsAppearance.setSelection(SettingsUtil.getAppearance(requireContext()).ordinal());
+        binding.settingsAppearance.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
+            @Override
+            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
+                Appearance appearance = Appearance.values()[position];
+                if(appearance == SettingsUtil.getAppearance(requireContext())) return;
+
+                SettingsUtil.setAppearance(requireContext(), appearance);
+                requireActivity().recreate();
+            }
+
+            @Override
+            public void onNothingSelected(AdapterView<?> parent) {}
+        });
+
         FabUtil.hideFabs(requireActivity());
 
         return binding.getRoot();
diff --git a/app/src/main/java/com/cringe_studios/cringe_authenticator/util/Appearance.java b/app/src/main/java/com/cringe_studios/cringe_authenticator/util/Appearance.java
new file mode 100644
index 0000000..99969ed
--- /dev/null
+++ b/app/src/main/java/com/cringe_studios/cringe_authenticator/util/Appearance.java
@@ -0,0 +1,35 @@
+package com.cringe_studios.cringe_authenticator.util;
+
+import androidx.annotation.StringRes;
+import androidx.appcompat.app.AppCompatDelegate;
+
+import com.cringe_studios.cringe_authenticator.R;
+
+public enum Appearance {
+
+    FOLLOW_SYSTEM(R.string.appearance_follow_system, AppCompatDelegate.MODE_NIGHT_FOLLOW_SYSTEM),
+    LIGHT(R.string.appearance_light, AppCompatDelegate.MODE_NIGHT_NO),
+    DARK(R.string.appearance_dark, AppCompatDelegate.MODE_NIGHT_YES),
+    ;
+
+    @StringRes
+    private int name;
+
+    @AppCompatDelegate.NightMode
+    private int value;
+
+    Appearance(@StringRes int name, @AppCompatDelegate.NightMode int value) {
+        this.name = name;
+        this.value = value;
+    }
+
+    @StringRes
+    public int getName() {
+        return name;
+    }
+
+    @AppCompatDelegate.NightMode
+    public int getValue() {
+        return value;
+    }
+}
diff --git a/app/src/main/java/com/cringe_studios/cringe_authenticator/util/SettingsUtil.java b/app/src/main/java/com/cringe_studios/cringe_authenticator/util/SettingsUtil.java
index fad2fcf..f96819d 100644
--- a/app/src/main/java/com/cringe_studios/cringe_authenticator/util/SettingsUtil.java
+++ b/app/src/main/java/com/cringe_studios/cringe_authenticator/util/SettingsUtil.java
@@ -188,6 +188,20 @@ public class SettingsUtil {
         }
     }
 
+    public static void setAppearance(Context ctx, Appearance appearance) {
+        SharedPreferences prefs = ctx.getSharedPreferences(GENERAL_PREFS_NAME, Context.MODE_PRIVATE);
+        prefs.edit().putString("appearance", appearance.name()).apply();
+    }
+
+    public static Appearance getAppearance(Context ctx) {
+        String themeId = ctx.getSharedPreferences(GENERAL_PREFS_NAME, Context.MODE_PRIVATE).getString("appearance", Appearance.FOLLOW_SYSTEM.name());
+        try {
+            return Appearance.valueOf(themeId);
+        }catch(IllegalArgumentException e) {
+            return Appearance.FOLLOW_SYSTEM;
+        }
+    }
+
     public static void setLocale(Context ctx, Locale locale) {
         SharedPreferences prefs = ctx.getSharedPreferences(GENERAL_PREFS_NAME, Context.MODE_PRIVATE);
         prefs.edit().putString("locale", locale.getLanguage()).apply();
diff --git a/app/src/main/java/com/cringe_studios/cringe_authenticator/util/ThemeUtil.java b/app/src/main/java/com/cringe_studios/cringe_authenticator/util/ThemeUtil.java
index e95bc9e..903655b 100644
--- a/app/src/main/java/com/cringe_studios/cringe_authenticator/util/ThemeUtil.java
+++ b/app/src/main/java/com/cringe_studios/cringe_authenticator/util/ThemeUtil.java
@@ -1,5 +1,7 @@
 package com.cringe_studios.cringe_authenticator.util;
 
+import android.annotation.SuppressLint;
+
 import androidx.appcompat.app.AppCompatActivity;
 import androidx.appcompat.app.AppCompatDelegate;
 
@@ -11,8 +13,7 @@ public class ThemeUtil {
         Theme theme = SettingsUtil.getTheme(activity);
         activity.setTheme(theme.getStyle());
 
-        // TODO: use settings
-        //AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_NO);
+        AppCompatDelegate.setDefaultNightMode(SettingsUtil.getAppearance(activity).getValue());
     }
 
 }
diff --git a/app/src/main/res/layout/activity_main.xml b/app/src/main/res/layout/activity_main.xml
index 8545503..d680b80 100644
--- a/app/src/main/res/layout/activity_main.xml
+++ b/app/src/main/res/layout/activity_main.xml
@@ -5,7 +5,6 @@
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:fitsSystemWindows="true"
-    android:background="@drawable/background_blue_green"
     tools:context=".MainActivity">
 
     <com.google.android.material.appbar.AppBarLayout
diff --git a/app/src/main/res/values-de-rDE/strings.xml b/app/src/main/res/values-de-rDE/strings.xml
index 315c785..46f319a 100644
--- a/app/src/main/res/values-de-rDE/strings.xml
+++ b/app/src/main/res/values-de-rDE/strings.xml
@@ -80,4 +80,7 @@
     <string name="theme_blue_yellow">Blau/Gelb</string>
     <string name="theme_green_yellow">Grün/Gelb</string>
     <string name="theme_orange_turquoise">Orange/Türkis</string>
+    <string name="appearance_follow_system">System folgen</string>
+    <string name="appearance_light">Hell</string>
+    <string name="appearance_dark">Dunkel</string>
 </resources>
\ No newline at end of file
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 09db239..91cea61 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -82,4 +82,7 @@
     <string name="theme_blue_yellow">Blue/Yellow</string>
     <string name="theme_green_yellow">Green/Yellow</string>
     <string name="theme_orange_turquoise">Orange/Turquoise</string>
+    <string name="appearance_dark">Dark</string>
+    <string name="appearance_light">Light</string>
+    <string name="appearance_follow_system">Follow system</string>
 </resources>
\ No newline at end of file