diff --git a/app/build.gradle b/app/build.gradle
index 6ee6915..cd4f8f2 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -6,8 +6,8 @@ android {
         applicationId "com.nicobrailo.pianoli"
         minSdkVersion 21
         targetSdkVersion 33
-        versionCode 20
-        versionName "1.20"
+        versionCode 21
+        versionName "1.21"
     }
 
 
diff --git a/app/src/main/java/com/nicobrailo/pianoli/PianoCanvas.java b/app/src/main/java/com/nicobrailo/pianoli/PianoCanvas.java
index 79b9ef8..4341f74 100644
--- a/app/src/main/java/com/nicobrailo/pianoli/PianoCanvas.java
+++ b/app/src/main/java/com/nicobrailo/pianoli/PianoCanvas.java
@@ -16,6 +16,7 @@
 import android.view.SurfaceHolder;
 import android.view.SurfaceView;
 
+import androidx.annotation.NonNull;
 import androidx.appcompat.app.AppCompatActivity;
 import androidx.core.graphics.ColorUtils;
 
@@ -32,29 +33,7 @@ class PianoCanvas extends SurfaceView implements SurfaceHolder.Callback {
     final AppConfigTrigger appConfigHandler;
     final int screen_size_y, screen_size_x;
 
-    final int[] KEY_COLORS = new int[]{
-            Color.rgb(220, 0, 0),     // Red 
-            Color.rgb(255, 135, 0),   // Orange
-            Color.rgb(255, 255, 0),   // Yellow
-            Color.rgb(80, 220, 20),   // Light Green
-            Color.rgb(0, 150, 150),   // Dark Green
-            Color.rgb(95, 70, 165),   // Purple
-            Color.rgb(213, 43, 149),  // Pink
-    };
-
-    /**
-     * Note that light green, orange and yellow have higher lightness than other colours, so adding just a little white doesn't have
-     * the desired effect. That is why they have a larger proportion of white added in.
-     */
-    final int[] PRESSED_KEY_COLORS = new int[]{
-            ColorUtils.blendARGB(KEY_COLORS[0], Color.WHITE, 0.5f),    // Red
-            ColorUtils.blendARGB(KEY_COLORS[1], Color.WHITE, 0.6f),    // Orange
-            ColorUtils.blendARGB(KEY_COLORS[2], Color.WHITE, 0.75f),   // Yellow
-            ColorUtils.blendARGB(KEY_COLORS[3], Color.WHITE, 0.6f),    // Light Green
-            ColorUtils.blendARGB(KEY_COLORS[4], Color.WHITE, 0.5f),    // Dark Green
-            ColorUtils.blendARGB(KEY_COLORS[5], Color.WHITE, 0.5f),    // Purple
-            ColorUtils.blendARGB(KEY_COLORS[6], Color.WHITE, 0.5f),    // Pink
-    };
+    final Theme theme;
 
     Map<Integer, Integer> touch_pointer_to_keys = new HashMap<>();
 
@@ -67,6 +46,8 @@ public PianoCanvas(Context context, AttributeSet as, int defStyle) {
         this.setFocusable(true);
         this.getHolder().addCallback(this);
 
+        theme = Theme.fromPreferences(context);
+
         final Point screen_size = new Point();
         final AppCompatActivity ctx;
         try {
@@ -107,9 +88,8 @@ void draw_all_keys(final Canvas canvas) {
 
         for (int i = 0; i < piano.get_keys_count(); i += 2) {
             // Draw big key
-            final int col_idx = (i / 2) % KEY_COLORS.length;
             Paint big_key_paint = new Paint();
-            big_key_paint.setColor(piano.is_key_pressed(i) ? PRESSED_KEY_COLORS[col_idx] : KEY_COLORS[col_idx]);
+            big_key_paint.setColor(theme.getColorForKey(i, piano.is_key_pressed(i)));
             draw_key(canvas, piano.get_area_for_key(i), big_key_paint);
         }
 
@@ -219,7 +199,7 @@ void draw_icon_on_black_key(final Canvas canvas, final Drawable icon, Integer ke
     }
 
     @Override
-    public void surfaceCreated(SurfaceHolder surfaceHolder) {
+    public void surfaceCreated(@NonNull SurfaceHolder surfaceHolder) {
         redraw(surfaceHolder);
     }
 
@@ -254,7 +234,7 @@ void resetPianoState() {
         // Something has gone wrong with the piano or canvas state, and our state is out of sync
         // with the real state of the world (eg somehow we missed a touch down or up event).
         // Try to reset the state and hope the app survives.
-        touch_pointer_to_keys.clear();;
+        touch_pointer_to_keys.clear();
         piano.resetState();
     }
 
@@ -336,12 +316,12 @@ public boolean onTouchEvent(MotionEvent event) {
 
 
     @Override
-    public void surfaceChanged(SurfaceHolder surfaceHolder, int i, int i1, int i2) {
+    public void surfaceChanged(@NonNull SurfaceHolder surfaceHolder, int i, int i1, int i2) {
 
     }
 
     @Override
-    public void surfaceDestroyed(SurfaceHolder surfaceHolder) {
+    public void surfaceDestroyed(@NonNull SurfaceHolder surfaceHolder) {
 
     }
 }
diff --git a/app/src/main/java/com/nicobrailo/pianoli/Preferences.java b/app/src/main/java/com/nicobrailo/pianoli/Preferences.java
index 8e83360..191f818 100644
--- a/app/src/main/java/com/nicobrailo/pianoli/Preferences.java
+++ b/app/src/main/java/com/nicobrailo/pianoli/Preferences.java
@@ -20,6 +20,8 @@ public class Preferences {
     private final static String PREF_SELECTED_SOUND_SET = "selectedSoundSet";
     private final static String PREF_SELECTED_MELODIES = "selectedMelodies";
     private final static String PREF_ENABLE_MELODIES = "enableMelodies";
+    private static final String DEFAULT_THEME = "boomwhacker";
+    private final static String PREF_THEME = "theme";
 
     /**
      * If none are selected, then we play all melodies.
@@ -43,6 +45,10 @@ public static List<Melody> selectedMelodies(Context context) {
         return melodies;
     }
 
+    public static String selectedTheme(Context context) {
+        return PreferenceManager.getDefaultSharedPreferences(context).getString(PREF_THEME, DEFAULT_THEME);
+    }
+
     public static boolean areMelodiesEnabled(Context context) {
         return PreferenceManager.getDefaultSharedPreferences(context).getBoolean(PREF_ENABLE_MELODIES, false);
     }
diff --git a/app/src/main/java/com/nicobrailo/pianoli/Theme.java b/app/src/main/java/com/nicobrailo/pianoli/Theme.java
new file mode 100644
index 0000000..2832064
--- /dev/null
+++ b/app/src/main/java/com/nicobrailo/pianoli/Theme.java
@@ -0,0 +1,66 @@
+package com.nicobrailo.pianoli;
+
+import android.content.Context;
+import android.graphics.Color;
+
+import androidx.core.graphics.ColorUtils;
+
+public class Theme {
+
+    private final int[] colours;
+    private final int[] pressedColours;
+
+    public static Theme fromPreferences(Context context) {
+        String selectedTheme = Preferences.selectedTheme(context);
+        switch (selectedTheme) {
+            case "black_and_white":
+                return BLACK_AND_WHITE;
+
+            default:
+                return BOOMWHACKER;
+        }
+    }
+
+    private static final int[] BOOMWHACKER_COLORS = new int[] {
+            Color.rgb(220, 0, 0),     // Red
+            Color.rgb(255, 135, 0),   // Orange
+            Color.rgb(255, 255, 0),   // Yellow
+            Color.rgb(80, 220, 20),   // Light Green
+            Color.rgb(0, 150, 150),   // Dark Green
+            Color.rgb(95, 70, 165),   // Purple
+            Color.rgb(213, 43, 149),  // Pink
+    };
+
+    /**
+     * Note that light green, orange and yellow have higher lightness than other colours,
+     * so adding just a little white doesn't have the desired effect.
+     * That is why they have a larger proportion of white added in.
+     */
+    private static final int[] BOOMWHACKER_PRESSED_COLORS = new int[] {
+        ColorUtils.blendARGB(BOOMWHACKER_COLORS[0], Color.WHITE, 0.5f),    // Red
+        ColorUtils.blendARGB(BOOMWHACKER_COLORS[1], Color.WHITE, 0.6f),    // Orange
+        ColorUtils.blendARGB(BOOMWHACKER_COLORS[2], Color.WHITE, 0.75f),   // Yellow
+        ColorUtils.blendARGB(BOOMWHACKER_COLORS[3], Color.WHITE, 0.6f),    // Light Green
+        ColorUtils.blendARGB(BOOMWHACKER_COLORS[4], Color.WHITE, 0.5f),    // Dark Green
+        ColorUtils.blendARGB(BOOMWHACKER_COLORS[5], Color.WHITE, 0.5f),    // Purple
+        ColorUtils.blendARGB(BOOMWHACKER_COLORS[6], Color.WHITE, 0.5f),    // Pink
+    };
+
+    private static final Theme BOOMWHACKER = new Theme(BOOMWHACKER_COLORS, BOOMWHACKER_PRESSED_COLORS);
+
+    private static final Theme BLACK_AND_WHITE = new Theme(
+            new int[] { Color.rgb(240, 240, 240) },
+            new int[] { Color.rgb(200, 200, 200) }
+    );
+
+    private Theme(int[] colors, int[] pressedColors) {
+        this.colours = colors;
+        this.pressedColours = pressedColors;
+    }
+
+    public int getColorForKey(int keyIndex, boolean isPressed) {
+        final int col_idx = (keyIndex / 2) % colours.length;
+        return isPressed ? pressedColours[col_idx] : colours[col_idx];
+    }
+
+}
diff --git a/app/src/main/res/values/donottranslate.xml b/app/src/main/res/values/donottranslate.xml
index f709012..d8fa01b 100644
--- a/app/src/main/res/values/donottranslate.xml
+++ b/app/src/main/res/values/donottranslate.xml
@@ -15,4 +15,14 @@
              and may not be as common as some of the other nursery rhymes. It is
              there to show what it sounds like to have longer melodies available. -->
     </string-array>
+
+    <string-array name="theme_entryValues">
+        <item>boomwhacker</item>
+        <item>black_and_white</item>
+    </string-array>
+
+    <string-array name="theme_entries">
+        <item>@string/theme_boomwhacker</item>
+        <item>@string/theme_black_and_white</item>
+    </string-array>
 </resources>
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 0b00748..3ae2ddf 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -20,4 +20,7 @@
     <string name="pref_enable_melodies">Auto play melodies</string>
     <string name="pref_selected_melodies">Available melodies</string>
     <string name="pref_selected_melodies_summary">List of melodies to cycle through</string>
+    <string name="theme">Theme</string>
+    <string name="theme_black_and_white">Black and White</string>
+    <string name="theme_boomwhacker">Boomwhacker</string>
 </resources>
diff --git a/app/src/main/res/xml/root_preferences.xml b/app/src/main/res/xml/root_preferences.xml
index 184285d..4f2be12 100644
--- a/app/src/main/res/xml/root_preferences.xml
+++ b/app/src/main/res/xml/root_preferences.xml
@@ -9,6 +9,14 @@
             app:title="@string/sound_set"
             app:useSimpleSummaryProvider="true"
             app:iconSpaceReserved="false" />
+        <ListPreference
+            app:defaultValue="boomwhacker"
+            app:key="theme"
+            app:title="@string/theme"
+            app:entries="@array/theme_entries"
+            app:entryValues="@array/theme_entryValues"
+            app:useSimpleSummaryProvider="true"
+            app:iconSpaceReserved="false" />
         <SwitchPreference
             app:defaultValue="false"
             app:key="enableMelodies"
diff --git a/fastlane/metadata/android/en-US/changelogs/21.txt b/fastlane/metadata/android/en-US/changelogs/21.txt
new file mode 100644
index 0000000..535b88a
--- /dev/null
+++ b/fastlane/metadata/android/en-US/changelogs/21.txt
@@ -0,0 +1,3 @@
+You can now choose different themes for your piano keys. Initial themes are the existing rainbow theme inspired by the Boomwhacker toys, and a Black and White theme. In the future, we will add more themes.
+
+Thanks to @juleskers for the input and encouragement to implement this.