diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 884ca57..a22859c 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -11,7 +11,7 @@
 		android:label="@string/app_name"
 		android:roundIcon="@mipmap/ic_launcher_round"
 		android:supportsRtl="true"
-		android:theme="@style/AppTheme.Dark">
+		android:theme="@style/AppTheme">
 	<activity android:name=".activities.MainActivity">
 		<intent-filter>
 			<action android:name="android.intent.action.MAIN" />
diff --git a/app/src/main/java/com/luca0n/joguitos/pluck/activities/BaseActivity.java b/app/src/main/java/com/luca0n/joguitos/pluck/activities/BaseActivity.java
index dc57b9f..fb51e3f 100644
--- a/app/src/main/java/com/luca0n/joguitos/pluck/activities/BaseActivity.java
+++ b/app/src/main/java/com/luca0n/joguitos/pluck/activities/BaseActivity.java
@@ -24,6 +24,7 @@ Contact us at <joguitos+pluck@luca0n.com>.
 package com.luca0n.joguitos.pluck.activities;
 
 import android.annotation.SuppressLint;
+import android.app.Activity;
 import android.content.Intent;
 import android.view.Menu;
 import android.view.MenuInflater;
@@ -35,48 +36,65 @@ import com.mikepenz.aboutlibraries.LibsBuilder;
 import androidx.appcompat.app.AppCompatActivity;
 import com.luca0n.joguitos.pluck.R;
 import com.luca0n.joguitos.pluck.settings.SettingsActivity;
+import com.luca0n.joguitos.pluck.util.UiUtil;
 
 @SuppressLint("Registered")
 public class BaseActivity extends AppCompatActivity {
+	public static final int REQUEST_ACTIVITY_CLOSED = 1;
 
-    @Override
-    public boolean onCreateOptionsMenu(Menu menu) {
-        MenuInflater inflater = getMenuInflater();
-        inflater.inflate(R.menu.app_menu, menu);
-        return true;
-    }
+	@Override
+	public boolean onCreateOptionsMenu(Menu menu) {
+		MenuInflater inflater = getMenuInflater();
+		inflater.inflate(R.menu.app_menu, menu);
+		return true;
+	}
 
-    @Override
-    public boolean onOptionsItemSelected(MenuItem item) {
-        switch (item.getItemId()) {
-            case R.id.settings:
-                onSettings();
-                return true;
-            case R.id.about:
-                onAbout();
-                return true;
-            case android.R.id.home:
-                onBackPressed();
-            default:
-                return super.onOptionsItemSelected(item);
-        }
-    }
+	@Override
+	public boolean onOptionsItemSelected(MenuItem item) {
+		switch (item.getItemId()) {
+			case R.id.settings:
+				onSettings();
+				return true;
+			case R.id.about:
+				onAbout();
+				return true;
+			case android.R.id.home:
+				onBackPressed();
+			default:
+				return super.onOptionsItemSelected(item);
+		}
+	}
 
-    private void onSettings() {
-        Intent intent = new Intent(this, SettingsActivity.class);
-        startActivity(intent);
-    }
+	@Override
+	public void onActivityResult(int requestCode, int resultCode, Intent extras){
+		switch (requestCode){
+			case REQUEST_ACTIVITY_CLOSED:
+				if (resultCode == Activity.RESULT_OK){
+					// Check if the theme changed.
+					recreate();
+				}
+				break;
+			default:
+				super.onActivityResult(requestCode, resultCode, extras);
+				break;
+		}
+	}
 
-    private void onAbout() {
-        String appName = getResources().getString(R.string.app_name);
-        String appDescription = getResources().getString(R.string.app_description);
+	private void onSettings() {
+		Intent intent = new Intent(this, SettingsActivity.class);
+		startActivityForResult(intent, REQUEST_ACTIVITY_CLOSED);
+	}
 
-        new LibsBuilder()
-                .withActivityStyle(Libs.ActivityStyle.LIGHT_DARK_TOOLBAR)
-                .withAboutIconShown(true)
-                .withAboutAppName(appName)
-                .withAboutVersionShownName(true)
-                .withAboutDescription(appDescription)
-                .start(this);
-    }
+	private void onAbout() {
+		String appName = getResources().getString(R.string.app_name);
+		String appDescription = getResources().getString(R.string.app_description);
+
+		new LibsBuilder()
+			.withActivityStyle(UiUtil.getTheme(this).equals(getString(R.string.pref_ui_theme_entryValues_dark)) ? Libs.ActivityStyle.DARK : Libs.ActivityStyle.LIGHT)
+			.withAboutIconShown(true)
+			.withAboutAppName(appName)
+			.withAboutVersionShownName(true)
+			.withAboutDescription(appDescription)
+			.start(this);
+	}
 }
diff --git a/app/src/main/java/com/luca0n/joguitos/pluck/activities/MainActivity.java b/app/src/main/java/com/luca0n/joguitos/pluck/activities/MainActivity.java
index 3cb9f2e..677f9ea 100644
--- a/app/src/main/java/com/luca0n/joguitos/pluck/activities/MainActivity.java
+++ b/app/src/main/java/com/luca0n/joguitos/pluck/activities/MainActivity.java
@@ -43,6 +43,7 @@ import com.luca0n.joguitos.pluck.trivia.TriviaCategory;
 import com.luca0n.joguitos.pluck.trivia.TriviaDifficulty;
 import com.luca0n.joguitos.pluck.trivia.TriviaQuery;
 import com.luca0n.joguitos.pluck.trivia.TriviaFilters;
+import com.luca0n.joguitos.pluck.util.UiUtil;
 
 public class MainActivity extends BaseActivity {
 
@@ -61,6 +62,7 @@ public class MainActivity extends BaseActivity {
 
 	@Override
 	protected void onCreate(Bundle savedInstanceState) {
+		UiUtil.setTheme(this);
 		super.onCreate(savedInstanceState);
 		setContentView(R.layout.activity_main);
 		ButterKnife.bind(this);
@@ -129,7 +131,7 @@ public class MainActivity extends BaseActivity {
 					.category(category)
 					.difficulty(difficulty)
 					.build());
-			startActivity(intent);
+			startActivityForResult(intent, BaseActivity.REQUEST_ACTIVITY_CLOSED);
 		});
 
 		// Create a String array that holds all options for spinnerNumber.
@@ -191,6 +193,10 @@ public class MainActivity extends BaseActivity {
 						.show();
 				}
 				break;
+			case BaseActivity.REQUEST_ACTIVITY_CLOSED:
+				// Check if the theme changed.
+				recreate();
+				break;
 			default:
 				super.onActivityResult(requestCode, resultCode, extras);
 				break;
diff --git a/app/src/main/java/com/luca0n/joguitos/pluck/activities/TriviaGameActivity.java b/app/src/main/java/com/luca0n/joguitos/pluck/activities/TriviaGameActivity.java
index 2007448..d566d90 100644
--- a/app/src/main/java/com/luca0n/joguitos/pluck/activities/TriviaGameActivity.java
+++ b/app/src/main/java/com/luca0n/joguitos/pluck/activities/TriviaGameActivity.java
@@ -23,6 +23,7 @@ Contact us at <joguitos+pluck@luca0n.com>.
 
 package com.luca0n.joguitos.pluck.activities;
 
+import android.app.Activity;
 import android.content.Intent;
 import android.content.res.ColorStateList;
 import android.graphics.PorterDuff;
@@ -66,6 +67,7 @@ import com.luca0n.joguitos.pluck.trivia.TriviaSource;
 import com.luca0n.joguitos.pluck.trivia.TriviaFilters;
 import com.luca0n.joguitos.pluck.util.ApiUtil;
 import com.luca0n.joguitos.pluck.util.SoundUtil;
+import com.luca0n.joguitos.pluck.util.UiUtil;
 
 public class TriviaGameActivity extends BaseActivity
 	implements IDownloadTriviaQuestionReceiver {
@@ -92,10 +94,13 @@ public class TriviaGameActivity extends BaseActivity
 
 	@Override
 	protected void onCreate(Bundle savedInstanceState) {
+		UiUtil.setTheme(this);
 		super.onCreate(savedInstanceState);
 		setContentView(R.layout.activity_trivia_game);
 		ButterKnife.bind(this);
 
+		setResult(Activity.RESULT_OK);
+
 		ActionBar actionBar = getSupportActionBar();
 		if (actionBar != null)
 			actionBar.setDisplayHomeAsUpEnabled(true);
diff --git a/app/src/main/java/com/luca0n/joguitos/pluck/activities/TriviaGameResultsActivity.java b/app/src/main/java/com/luca0n/joguitos/pluck/activities/TriviaGameResultsActivity.java
index bdfc09c..5c98e70 100644
--- a/app/src/main/java/com/luca0n/joguitos/pluck/activities/TriviaGameResultsActivity.java
+++ b/app/src/main/java/com/luca0n/joguitos/pluck/activities/TriviaGameResultsActivity.java
@@ -31,55 +31,57 @@ import butterknife.BindView;
 import butterknife.ButterKnife;
 import com.luca0n.joguitos.pluck.R;
 import com.luca0n.joguitos.pluck.trivia.TriviaGame;
+import com.luca0n.joguitos.pluck.util.UiUtil;
 
 public class TriviaGameResultsActivity extends BaseActivity {
-    static final String EXTRA_TRIVIA_GAME = "extra_trivia_game";
+	static final String EXTRA_TRIVIA_GAME = "extra_trivia_game";
 
-    @BindView(R.id.text_results_correct)
-    TextView textResultsCorrect;
-    @BindView(R.id.text_results_wrong)
-    TextView textResultsWrong;
-    @BindView(R.id.text_results_total)
-    TextView textResultsTotal;
-		@BindView(R.id.text_results_time_elapsed)
-		TextView textResultsTimeElapsed;
-    @BindView(R.id.button_return_to_menu)
-    Button buttonReturnToMenu;
+	@BindView(R.id.text_results_correct)
+	TextView textResultsCorrect;
+	@BindView(R.id.text_results_wrong)
+	TextView textResultsWrong;
+	@BindView(R.id.text_results_total)
+	TextView textResultsTotal;
+	@BindView(R.id.text_results_time_elapsed)
+	TextView textResultsTimeElapsed;
+	@BindView(R.id.button_return_to_menu)
+	Button buttonReturnToMenu;
 
-    @Override
-    protected void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        setContentView(R.layout.activity_trivia_game_results);
-        ButterKnife.bind(this);
+	@Override
+	protected void onCreate(Bundle savedInstanceState) {
+		UiUtil.setTheme(this);
+		super.onCreate(savedInstanceState);
+		setContentView(R.layout.activity_trivia_game_results);
+		ButterKnife.bind(this);
 
-        Bundle bundle = getIntent().getExtras();
-        TriviaGame game = (TriviaGame) bundle.get(EXTRA_TRIVIA_GAME);
+		Bundle bundle = getIntent().getExtras();
+		TriviaGame game = (TriviaGame) bundle.get(EXTRA_TRIVIA_GAME);
 
-        int correctTotal = 0;
+		int correctTotal = 0;
 
-        for (boolean result : game.getResults()) {
-            if (result) {
-                correctTotal++;
-            }
-        }
+		for (boolean result : game.getResults()) {
+			if (result) {
+				correctTotal++;
+			}
+		}
 
-				// Calculate the difference between startEpoch and endEpoch
-				float timeDifference = (game.getEndEpoch() - game.getStartEpoch())/1000F;
+		// Calculate the difference between startEpoch and endEpoch
+		float timeDifference = (game.getEndEpoch() - game.getStartEpoch())/1000F;
 
-        textResultsCorrect.setText(String.valueOf(correctTotal));
-        textResultsWrong.setText(String.valueOf(game.getQuestionsCount() - correctTotal));
-        textResultsTotal.setText(String.valueOf(game.getQuestionsCount()));
-				if (timeDifference < 60000L)
-					// Use the "n seconds" string since the time difference was less than 60 seconds.
-					textResultsTimeElapsed.setText(
-							String.format(getString(R.string.ui_results_time_elapsed_format_seconds), timeDifference)
-							);
-				else
-					// Use the "n minutes" string since the time difference was equal to or more than 60 seconds.
-					textResultsTimeElapsed.setText(
-							String.format(getString(R.string.ui_results_time_elapsed_format_minutes), timeDifference / 60F)
-							);
+		textResultsCorrect.setText(String.valueOf(correctTotal));
+		textResultsWrong.setText(String.valueOf(game.getQuestionsCount() - correctTotal));
+		textResultsTotal.setText(String.valueOf(game.getQuestionsCount()));
+		if (timeDifference < 60000L)
+			// Use the "n seconds" string since the time difference was less than 60 seconds.
+			textResultsTimeElapsed.setText(
+					String.format(getString(R.string.ui_results_time_elapsed_format_seconds), timeDifference)
+					);
+		else
+			// Use the "n minutes" string since the time difference was equal to or more than 60 seconds.
+			textResultsTimeElapsed.setText(
+					String.format(getString(R.string.ui_results_time_elapsed_format_minutes), timeDifference / 60F)
+					);
 
-        buttonReturnToMenu.setOnClickListener(v -> finish());
-    }
+		buttonReturnToMenu.setOnClickListener(v -> finish());
+	}
 }
diff --git a/app/src/main/java/com/luca0n/joguitos/pluck/settings/SettingsActivity.java b/app/src/main/java/com/luca0n/joguitos/pluck/settings/SettingsActivity.java
index 34e362d..8c049ce 100644
--- a/app/src/main/java/com/luca0n/joguitos/pluck/settings/SettingsActivity.java
+++ b/app/src/main/java/com/luca0n/joguitos/pluck/settings/SettingsActivity.java
@@ -23,6 +23,7 @@ Contact us at <joguitos+pluck@luca0n.com>.
 
 package com.luca0n.joguitos.pluck.settings;
 
+import android.app.Activity;
 import android.os.Bundle;
 import android.view.MenuItem;
 
@@ -30,19 +31,23 @@ import androidx.annotation.Nullable;
 import androidx.appcompat.app.ActionBar;
 import androidx.appcompat.app.AppCompatActivity;
 
+import com.luca0n.joguitos.pluck.util.UiUtil;
+
 public class SettingsActivity extends AppCompatActivity {
 	@Override
 	protected void onCreate(@Nullable Bundle savedInstanceState) {
+		UiUtil.setTheme(this);
 		super.onCreate(savedInstanceState);
 
 		ActionBar actionBar = getSupportActionBar();
 		if (actionBar != null)
 			actionBar.setDisplayHomeAsUpEnabled(true);
 
-		getFragmentManager()
+		getSupportFragmentManager()
 			.beginTransaction()
 			.replace(android.R.id.content, new SettingsFragment())
 			.commit();
+		setResult(Activity.RESULT_OK);
 	}
 
 	@Override
diff --git a/app/src/main/java/com/luca0n/joguitos/pluck/settings/SettingsFragment.java b/app/src/main/java/com/luca0n/joguitos/pluck/settings/SettingsFragment.java
index 6c23564..ec15150 100644
--- a/app/src/main/java/com/luca0n/joguitos/pluck/settings/SettingsFragment.java
+++ b/app/src/main/java/com/luca0n/joguitos/pluck/settings/SettingsFragment.java
@@ -24,15 +24,32 @@ Contact us at <joguitos+pluck@luca0n.com>.
 package com.luca0n.joguitos.pluck.settings;
 
 import android.os.Bundle;
-import android.preference.PreferenceFragment;
+import androidx.preference.PreferenceFragmentCompat;
 
 import androidx.annotation.Nullable;
-import com.luca0n.joguitos.pluck.R;
+import androidx.preference.ListPreference;
+import androidx.preference.Preference;
 
-public class SettingsFragment extends PreferenceFragment {
-    @Override
-    public void onCreate(@Nullable Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        addPreferencesFromResource(R.xml.preferences);
-    }
+import com.luca0n.joguitos.pluck.R;
+import com.luca0n.joguitos.pluck.util.UiUtil;
+
+public class SettingsFragment extends PreferenceFragmentCompat {
+	@Override
+	public void onCreate(@Nullable Bundle savedInstanceState) {
+		super.onCreate(savedInstanceState);
+	}
+
+	@Override
+	public void onCreatePreferences(Bundle savedInstanceState, String rootKey){
+		addPreferencesFromResource(R.xml.preferences);
+		// Listen for theme preference changes
+		ListPreference preferenceTheme = (ListPreference) findPreference(getString(R.string.pref_ui_theme));
+		preferenceTheme.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener(){
+			@Override
+			public boolean onPreferenceChange(Preference preference, Object newValue){
+				getActivity().recreate();
+				return true;
+			}
+		});
+	}
 }
diff --git a/app/src/main/java/com/luca0n/joguitos/pluck/util/UiUtil.java b/app/src/main/java/com/luca0n/joguitos/pluck/util/UiUtil.java
new file mode 100644
index 0000000..9ad1378
--- /dev/null
+++ b/app/src/main/java/com/luca0n/joguitos/pluck/util/UiUtil.java
@@ -0,0 +1,61 @@
+/*
+Pluck: an open source trivia game for Android
+
+Copyright (C) 2021 Joguitos do luca0N!
+
+This program is free software: you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free Software
+Foundation, either version 3 of the License, or (at your option) any later
+version.
+
+This program is distributed in the hope that it will be useful, but WITHOUT
+ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along with
+this program. If not, see <https://www.gnu.org/licenses/>.
+
+This game is a fork of LibreTrivia, and its source code is available at
+<https://github.com/tryton-vanmeer/LibreTrivia>.
+
+Contact us at <joguitos+pluck@luca0n.com>.
+*/
+
+package com.luca0n.joguitos.pluck.util;
+
+import android.content.Context;
+import android.content.SharedPreferences;
+import android.preference.PreferenceManager;
+
+import com.luca0n.joguitos.pluck.R;
+
+public class UiUtil {
+	/**
+	 * Applies the theme selected by the user to the context.
+	 * @param context The activity context.
+	 * @since 2021-03-17
+	 */
+	public static void setTheme(Context context){
+		SharedPreferences s = PreferenceManager.getDefaultSharedPreferences(context.getApplicationContext());
+
+		String dark = context.getString(R.string.pref_ui_theme_entryValues_dark),
+					theme = getTheme(context);
+
+		if (theme.equals(dark))
+			context.setTheme(R.style.AppTheme_Dark);
+		else
+			context.setTheme(R.style.AppTheme);
+	}
+
+	/**
+	 * @return The app theme selected by the user.
+	 * @param context The activity context.
+	 * @since 2021-03-17
+	 */
+	public static String getTheme(Context context){
+		SharedPreferences s = PreferenceManager.getDefaultSharedPreferences(context.getApplicationContext());
+		String themeKey = context.getString(R.string.pref_ui_theme),
+					 themeLight = context.getString(R.string.pref_ui_theme_entryValues_light);
+		return s.getString(themeKey, themeLight);
+	}
+}
diff --git a/app/src/main/res/values/arrays.xml b/app/src/main/res/values/arrays.xml
new file mode 100644
index 0000000..12972ab
--- /dev/null
+++ b/app/src/main/res/values/arrays.xml
@@ -0,0 +1,30 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+Pluck: an open source trivia game for Android
+
+Copyright (C) 2021 Joguitos do luca0N!
+
+This program is free software: you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free Software
+Foundation, either version 3 of the License, or (at your option) any later
+version.
+
+This program is distributed in the hope that it will be useful, but WITHOUT
+ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along with
+this program. If not, see <https://www.gnu.org/licenses/>.
+
+This game is a fork of LibreTrivia, and its source code is available at
+<https://github.com/tryton-vanmeer/LibreTrivia>.
+
+Contact us at <joguitos+pluck@luca0n.com>.
+-->
+
+<resources>
+	<string-array name="pref_ui_theme_entryValues">
+		<item>pref_ui_theme_entryValues_light</item>
+		<item>pref_ui_theme_entryValues_dark</item>
+	</string-array>
+</resources>
diff --git a/app/src/main/res/values/pref_keys.xml b/app/src/main/res/values/pref_keys.xml
index c7bb272..3e6969e 100644
--- a/app/src/main/res/values/pref_keys.xml
+++ b/app/src/main/res/values/pref_keys.xml
@@ -28,4 +28,8 @@ Contact us at <joguitos+pluck@luca0n.com>.
 		<string name="pref_network_tor">pref_network_tor</string>
 		<string name="pref_network_server">pref_network_server</string>
 		<string name="pref_network_server_default">https://opentdb.com/api.php</string>
+		<string name="pref_ui_theme">pref_ui_theme</string>
+		<string name="pref_ui_theme_entryValues_light">pref_ui_theme_entryValues_light</string>
+		<string name="pref_ui_theme_entryValues_dark">pref_ui_theme_entryValues_dark</string>
+		<string name="pref_ui_theme_default">pref_ui_theme_entryValues_light</string>
 </resources>
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 2fab1c0..91cacb0 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -23,97 +23,105 @@ Contact us at <joguitos+pluck@luca0n.com>.
 -->
 
 <resources>
-    <string name="app_name" translatable="false">Pluck</string>
-    <string name="app_description">An open source trivia game.</string>
+	<string name="app_name" translatable="false">Pluck</string>
+	<string name="app_description">An open source trivia game.</string>
 
-    <!-- Category Names -->
-    <string name="category_general_knowledge">General Knowledge</string>
-    <string name="category_entertainment_books">Entertainment: Books</string>
-    <string name="category_entertainment_film">Entertainment: Film</string>
-    <string name="category_entertainment_music">Entertainment: Music</string>
-    <string name="category_entertainment_musicals_theatres">Entertainment: Musicals &amp; Theatres</string>
-    <string name="category_entertainment_television">Entertainment: Television</string>
-    <string name="category_entertainment_video_games">Entertainment: Video Games</string>
-    <string name="category_entertainment_board_games">Entertainment: Board Games</string>
-    <string name="category_entertainment_japanese_anime_manga">Entertainment: Japanese Anime &amp; Manga</string>
-    <string name="category_entertainment_cartoon_animations">Entertainment: Cartoons &amp; Animation</string>
-    <string name="category_entertainment_comics">Entertainment: Comics</string>
-    <string name="category_science_nature">Science &amp; Nature</string>
-    <string name="category_science_computers">Science: Computers</string>
-    <string name="category_science_mathematics">Science: Mathematics</string>
-    <string name="category_science_gadgets">Science: Gadgets</string>
-    <string name="category_mythology">Mythology</string>
-    <string name="category_sports">Sports</string>
-    <string name="category_geography">Geography</string>
-    <string name="category_history">History</string>
-    <string name="category_politics">Politics</string>
-    <string name="category_art">Art</string>
-    <string name="category_celebrities">Celebrities</string>
-    <string name="category_animals">Animals</string>
-    <string name="category_vehicles">Vehicles</string>
+	<!-- Category Names -->
+	<string name="category_general_knowledge">General Knowledge</string>
+	<string name="category_entertainment_books">Entertainment: Books</string>
+	<string name="category_entertainment_film">Entertainment: Film</string>
+	<string name="category_entertainment_music">Entertainment: Music</string>
+	<string name="category_entertainment_musicals_theatres">Entertainment: Musicals &amp; Theatres</string>
+	<string name="category_entertainment_television">Entertainment: Television</string>
+	<string name="category_entertainment_video_games">Entertainment: Video Games</string>
+	<string name="category_entertainment_board_games">Entertainment: Board Games</string>
+	<string name="category_entertainment_japanese_anime_manga">Entertainment: Japanese Anime &amp; Manga</string>
+	<string name="category_entertainment_cartoon_animations">Entertainment: Cartoons &amp; Animation</string>
+	<string name="category_entertainment_comics">Entertainment: Comics</string>
+	<string name="category_science_nature">Science &amp; Nature</string>
+	<string name="category_science_computers">Science: Computers</string>
+	<string name="category_science_mathematics">Science: Mathematics</string>
+	<string name="category_science_gadgets">Science: Gadgets</string>
+	<string name="category_mythology">Mythology</string>
+	<string name="category_sports">Sports</string>
+	<string name="category_geography">Geography</string>
+	<string name="category_history">History</string>
+	<string name="category_politics">Politics</string>
+	<string name="category_art">Art</string>
+	<string name="category_celebrities">Celebrities</string>
+	<string name="category_animals">Animals</string>
+	<string name="category_vehicles">Vehicles</string>
 
-    <!-- Difficulty Names -->
-    <string name="difficulty_easy">Easy</string>
-    <string name="difficulty_medium">Medium</string>
-    <string name="difficulty_hard">Hard</string>
+	<!-- Difficulty Names -->
+	<string name="difficulty_easy">Easy</string>
+	<string name="difficulty_medium">Medium</string>
+	<string name="difficulty_hard">Hard</string>
 
-    <!-- Question Type Names -->
-    <string name="question_type_multiple">Multiple Choice</string>
-    <string name="question_type_boolean">True / False</string>
+	<!-- Question Type Names -->
+	<string name="question_type_multiple">Multiple Choice</string>
+	<string name="question_type_boolean">True / False</string>
 
-		<!-- Source Names -->
-		<string name="source_server">Server</string>
-		<string name="source_file">File</string>
+	<!-- Source Names -->
+	<string name="source_server">Server</string>
+	<string name="source_file">File</string>
 
-    <!-- UI -->
-    <string name="ui_settings">Settings</string>
-    <string name="ui_about">About</string>
-    <string name="ui_play">Play</string>
-    <string name="ui_start_game">Start Game</string>
-		<string name="ui_any">Any</string>
-		<string name="ui_all">All</string>
-    <string name="ui_true">True</string>
-    <string name="ui_false">False</string>
-    <string name="ui_correct">Correct</string>
-    <string name="ui_wrong">Wrong</string>
-    <string name="ui_amount">Questions</string>
-    <string name="ui_category">Category</string>
-    <string name="ui_difficulty">Difficulty</string>
-    <string name="ui_question_progress">%1$d⁄%2$d</string>
-    <string name="ui_quit_game">Quit Game</string>
-    <string name="ui_quit_game_msg">Are you sure you want to quit this game?</string>
-    <string name="ui_results_correct">Correct Answers</string>
-    <string name="ui_results_wrong">Wrong Answers</string>
-		<string name="ui_results_total">Total Questions</string>
-		<string name="ui_results_time_elapsed">Time Elapsed</string>
-		<string name="ui_results_time_elapsed_format_seconds">%.1f seconds</string>
-		<string name="ui_results_time_elapsed_format_minutes">%.1f minutes</string>
-		<string name="ui_return_to_menu">Return To Menu</string>
-		<string name="ui_source">Source</string>
-		<string name="ui_source_about">This value specifies where the game should retrieve trivia data. By default, the game gathers trivia data from a server, but you can load trivia files with the "File" source option.</string>
-		<string name="ui_network_notice">Notice: when using a server as the game source, this game connects to Open Trivia Database by default to gather trivia questions. Open Trivia Database is a collection of user-contributed questions that are licensed under the Creative Commons Attribution-ShareAlike 4.0 International (CC-BY-SA 4.0) license.\n\nYou can select a custom server in the game settings.\n\nIf you want to open a trivia file instead of getting trivia questions from a server, select "File" as the trivia game source above.</string>
+	<!-- UI -->
+	<string name="ui_settings">Settings</string>
+	<string name="ui_about">About</string>
+	<string name="ui_play">Play</string>
+	<string name="ui_start_game">Start Game</string>
+	<string name="ui_any">Any</string>
+	<string name="ui_all">All</string>
+	<string name="ui_true">True</string>
+	<string name="ui_false">False</string>
+	<string name="ui_correct">Correct</string>
+	<string name="ui_wrong">Wrong</string>
+	<string name="ui_amount">Questions</string>
+	<string name="ui_category">Category</string>
+	<string name="ui_difficulty">Difficulty</string>
+	<string name="ui_question_progress">%1$d⁄%2$d</string>
+	<string name="ui_quit_game">Quit Game</string>
+	<string name="ui_quit_game_msg">Are you sure you want to quit this game?</string>
+	<string name="ui_results_correct">Correct Answers</string>
+	<string name="ui_results_wrong">Wrong Answers</string>
+	<string name="ui_results_total">Total Questions</string>
+	<string name="ui_results_time_elapsed">Time Elapsed</string>
+	<string name="ui_results_time_elapsed_format_seconds">%.1f seconds</string>
+	<string name="ui_results_time_elapsed_format_minutes">%.1f minutes</string>
+	<string name="ui_return_to_menu">Return To Menu</string>
+	<string name="ui_source">Source</string>
+	<string name="ui_source_about">This value specifies where the game should retrieve trivia data. By default, the game gathers trivia data from a server, but you can load trivia files with the "File" source option.</string>
+	<string name="ui_network_notice">Notice: when using a server as the game source, this game connects to Open Trivia Database by default to gather trivia questions. Open Trivia Database is a collection of user-contributed questions that are licensed under the Creative Commons Attribution-ShareAlike 4.0 International (CC-BY-SA 4.0) license.\n\nYou can select a custom server in the game settings.\n\nIf you want to open a trivia file instead of getting trivia questions from a server, select "File" as the trivia game source above.</string>
 
-		<!-- Error Strings -->
-		<string name="error">Error</string>
-		<string name="error_network"><b>Network error!</b>\n\nCould not connect to a network. Check if your custom server address is correct. If Tor is enabled in the game settings, check if Orbot is running and then try again.</string>
-		<string name="error_no_trivia_results"><b>No trivia results!</b>\n\nWas not able to find trivia questions that satisfied all options.</string>
-		<string name="error_server_response_invalid"><b>Server response error!</b>\n\nCould not parse the server response. The server response may be in a unsupported version. If you are using a custom server, make sure the server address points to a valid address and then try again.</string>
-		<string name="error_unknown"><b>An unknown error occurred!</b></string>
-		<string name="error_source_file_android_version_unsupported">Trivia files are not supported in this version of Android.</string>
-		<string name="error_trivia_file_invalid"><b>Invalid trivia file!</b>\n\nTrivia files should be in a plain text JSON format.</string>
-		<string name="error_trivia_file_fetch_unknown">An unknown error occurred while attempting to read the opened file.</string>
-		<string name="error_option_all_unavailable">The selected question amount is only available for the "File" trivia game source.</string>
+	<!-- Error Strings -->
+	<string name="error">Error</string>
+	<string name="error_network"><b>Network error!</b>\n\nCould not connect to a network. Check if your custom server address is correct. If Tor is enabled in the game settings, check if Orbot is running and then try again.</string>
+	<string name="error_no_trivia_results"><b>No trivia results!</b>\n\nWas not able to find trivia questions that satisfied all options.</string>
+	<string name="error_server_response_invalid"><b>Server response error!</b>\n\nCould not parse the server response. The server response may be in a unsupported version. If you are using a custom server, make sure the server address points to a valid address and then try again.</string>
+	<string name="error_unknown"><b>An unknown error occurred!</b></string>
+	<string name="error_source_file_android_version_unsupported">Trivia files are not supported in this version of Android.</string>
+	<string name="error_trivia_file_invalid"><b>Invalid trivia file!</b>\n\nTrivia files should be in a plain text JSON format.</string>
+	<string name="error_trivia_file_fetch_unknown">An unknown error occurred while attempting to read the opened file.</string>
+	<string name="error_option_all_unavailable">The selected question amount is only available for the "File" trivia game source.</string>
 
-    <string name="title_activity_settings">Settings</string>
+	<string name="title_activity_settings">Settings</string>
 
-    <!-- Setting Strings-->
-    <string name="pref_category_sound_title">Sound</string>
-		<string name="pref_sound_answer_title">Answer Sound Effect</string>
-		<string name="pref_sound_answer_summary">Toggles game sound effects.</string>
+	<!-- Setting Strings-->
+	<string name="pref_category_sound_title">Sound</string>
+	<string name="pref_sound_answer_title">Answer Sound Effect</string>
+	<string name="pref_sound_answer_summary">Toggles game sound effects.</string>
 
-		<string name="pref_category_network_title">Network</string>
-		<string name="pref_network_tor_title">Connect Using Tor</string>
-		<string name="pref_network_tor_summary">Retrieves trivia data via the Tor network. Requires Orbot (recommended) or a Tor daemon with a SOCKS5 proxy listening on port 9050.</string>
-		<string name="pref_network_server_title">Server Address</string>
-		<string name="pref_network_server_summary">Specifies the server location used by the game to fetch questions when using a server as the trivia source. Leave this setting empty to use the default server.</string>
+	<string name="pref_category_network_title">Network</string>
+	<string name="pref_network_tor_title">Connect Using Tor</string>
+	<string name="pref_network_tor_summary">Retrieves trivia data via the Tor network. Requires Orbot (recommended) or a Tor daemon with a SOCKS5 proxy listening on port 9050.</string>
+	<string name="pref_network_server_title">Server Address</string>
+	<string name="pref_network_server_summary">Specifies the server location used by the game to fetch questions when using a server as the trivia source. Leave this setting empty to use the default server.</string>
+
+	<string name="pref_category_ui_title">Interface</string>
+	<string name="pref_ui_theme_title">Theme</string>
+	<string name="pref_ui_theme_summary">Defines the game theme.</string>
+	<string-array name="pref_ui_theme_entries">
+		<item>Light</item>
+		<item>Dark</item>
+	</string-array>
 </resources>
diff --git a/app/src/main/res/xml/preferences.xml b/app/src/main/res/xml/preferences.xml
index 4c35560..242f038 100644
--- a/app/src/main/res/xml/preferences.xml
+++ b/app/src/main/res/xml/preferences.xml
@@ -48,4 +48,14 @@ Contact us at <joguitos+pluck@luca0n.com>.
 			android:title="@string/pref_network_tor_title"
 			android:summary="@string/pref_network_tor_summary" />
 	</PreferenceCategory>
+	<PreferenceCategory
+		android:title="@string/pref_category_ui_title">
+		<ListPreference
+			android:defaultValue="@string/pref_ui_theme_default"
+			android:key="@string/pref_ui_theme"
+			android:title="@string/pref_ui_theme_title"
+			android:summary="@string/pref_ui_theme_summary"
+			android:entries="@array/pref_ui_theme_entries"
+			android:entryValues="@array/pref_ui_theme_entryValues" />
+	</PreferenceCategory>
 </PreferenceScreen>