diff --git a/src/main/java/envoy/client/event/Event.java b/src/main/java/envoy/client/event/Event.java
index 9db2477..4a3264d 100644
--- a/src/main/java/envoy/client/event/Event.java
+++ b/src/main/java/envoy/client/event/Event.java
@@ -1,10 +1,10 @@
 package envoy.client.event;
 
 /**
- * Project: <strong>envoy-clientChess</strong><br>
- * File: <strong>Event.javaEvent.java</strong><br>
+ * Project: <strong>envoy-client</strong><br>
+ * File: <strong>Event.java</strong><br>
  * Created: <strong>04.12.2019</strong><br>
- * 
+ *
  * @author Kai S. K. Engelbart
  * @since Envoy v0.2-alpha
  */
diff --git a/src/main/java/envoy/client/event/EventBus.java b/src/main/java/envoy/client/event/EventBus.java
index f6da3f5..06b385f 100644
--- a/src/main/java/envoy/client/event/EventBus.java
+++ b/src/main/java/envoy/client/event/EventBus.java
@@ -1,8 +1,9 @@
 package envoy.client.event;
 
 import java.util.ArrayList;
-import java.util.Arrays;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 
 /**
  * This class handles events by allowing {@link EventHandler} object to register
@@ -10,11 +11,12 @@ import java.util.List;
  * bus.<br>
  * <br>
  * The event bus is a singleton and can be used across the entire application to
- * guarantee the propagation of events.
+ * guarantee the propagation of events.<br>
+ *
  * Project: <strong>envoy-client</strong><br>
  * File: <strong>EventBus.java</strong><br>
  * Created: <strong>04.12.2019</strong><br>
- * 
+ *
  * @author Kai S. K. Engelbart
  * @since Envoy v0.2-alpha
  */
@@ -22,9 +24,10 @@ public class EventBus {
 
 	/**
 	 * Contains all {@link EventHandler} instances registered at this
-	 * {@link EventBus}.
+	 * {@link EventBus} as values mapped to by their supported {@link Event}
+	 * classes.
 	 */
-	private List<EventHandler> handlers = new ArrayList<>();
+	private Map<Class<? extends Event<?>>, List<EventHandler>> handlers = new HashMap<>();
 
 	/**
 	 * The singleton instance of this {@link EventBus} that is used across the
@@ -46,26 +49,33 @@ public class EventBus {
 	public static EventBus getInstance() { return eventBus; }
 
 	/**
-	 * Registers a list of {@link EventHandler} objects to be notified when a
-	 * {@link Event} is dispatched that they are subscribed to.
-	 * 
-	 * @param handlers the {@link EventHandler} objects to register
+	 * Registers an {@link EventHandler} to be notified when a
+	 * {@link Event} of a certain type is dispatched.
+	 *
+	 * @param eventClass the class which the {@link EventHandler} is subscribed to
+	 * @param handler    the {@link EventHandler} to register
 	 * @since Envoy v0.2-alpha
 	 */
-	public void register(EventHandler... handlers) { this.handlers.addAll(Arrays.asList(handlers)); }
+	public void register(Class<? extends Event<?>> eventClass, EventHandler handler) {
+		if (!handlers.containsKey(eventClass)) handlers.put(eventClass, new ArrayList<>());
+		handlers.get(eventClass).add(handler);
+	}
 
 	/**
 	 * Dispatches a {@link Event} to every {@link EventHandler} subscribed to it.
-	 * 
+	 *
 	 * @param event the {@link Event} to dispatch
 	 * @since Envoy v0.2-alpha
 	 */
-	public void dispatch(Event<?> event) { handlers.stream().filter(h -> h.supports().contains(event.getClass())).forEach(h -> h.handle(event)); }
+	public void dispatch(Event<?> event) {
+		handlers.keySet().stream().filter(event.getClass()::isAssignableFrom).map(handlers::get).flatMap(List::stream).forEach(h -> h.handle(event));
+	}
 
 	/**
-	 * @return a list of all {@link EventHandler} instances currently registered at
-	 *         this {@link EventBus}
+	 * @return a map of all {@link EventHandler} instances currently registered at
+	 *         this {@link EventBus} with the {@link Event} classes they are
+	 *         subscribed to as keys
 	 * @since Envoy v0.2-alpha
 	 */
-	public List<EventHandler> getHandlers() { return handlers; }
+	public Map<Class<? extends Event<?>>, List<EventHandler>> getHandlers() { return handlers; }
 }
diff --git a/src/main/java/envoy/client/event/EventHandler.java b/src/main/java/envoy/client/event/EventHandler.java
index a6e5b81..ef3daea 100644
--- a/src/main/java/envoy/client/event/EventHandler.java
+++ b/src/main/java/envoy/client/event/EventHandler.java
@@ -1,25 +1,18 @@
 package envoy.client.event;
 
-import java.util.Set;
-
 /**
  * Project: <strong>envoy-clientChess</strong><br>
  * File: <strong>EventHandler.javaEvent.java</strong><br>
  * Created: <strong>04.12.2019</strong><br>
- * 
+ *
  * @author Kai S. K. Engelbart
  */
 public interface EventHandler {
 
 	/**
 	 * Consumes an event dispatched by the event bus.
-	 * 
+	 *
 	 * @param event The event dispatched by the event bus, only of supported type
 	 */
 	void handle(Event<?> event);
-
-	/**
-	 * @return A set of classes this class is supposed to handle in events
-	 */
-	Set<Class<? extends Event<?>>> supports();
 }
diff --git a/src/main/java/envoy/client/event/ThemeChangeEvent.java b/src/main/java/envoy/client/event/ThemeChangeEvent.java
new file mode 100644
index 0000000..d3ba96b
--- /dev/null
+++ b/src/main/java/envoy/client/event/ThemeChangeEvent.java
@@ -0,0 +1,20 @@
+package envoy.client.event;
+
+import envoy.client.ui.Theme;
+
+/**
+ * Project: <strong>envoy-client</strong><br>
+ * File: <strong>ThemeChangeEvent.java</strong><br>
+ * Created: <strong>15 Dec 2019</strong><br>
+ *
+ * @author Kai S. K. Engelbart
+ */
+public class ThemeChangeEvent implements Event<Theme> {
+
+	private final Theme theme;
+
+	public ThemeChangeEvent(Theme theme) { this.theme = theme; }
+
+	@Override
+	public Theme get() { return theme; }
+}
diff --git a/src/main/java/envoy/client/ui/ChatWindow.java b/src/main/java/envoy/client/ui/ChatWindow.java
index 9595d43..49c73df 100644
--- a/src/main/java/envoy/client/ui/ChatWindow.java
+++ b/src/main/java/envoy/client/ui/ChatWindow.java
@@ -30,6 +30,8 @@ import envoy.client.Client;
 import envoy.client.Config;
 import envoy.client.LocalDB;
 import envoy.client.Settings;
+import envoy.client.event.EventBus;
+import envoy.client.event.ThemeChangeEvent;
 import envoy.schema.Message;
 import envoy.schema.User;
 
@@ -166,7 +168,6 @@ public class ChatWindow extends JFrame {
 		settingsButton.addActionListener((evt) -> {
 			try {
 				SettingsScreen.open();
-				changeChatWindowColors(Settings.getInstance().getCurrentTheme());
 			} catch (Exception e) {
 				SettingsScreen.open();
 				logger.log(Level.WARNING, "An error occured while opening the settings screen", e);
@@ -220,11 +221,13 @@ public class ChatWindow extends JFrame {
 		gbc_userList.anchor	= GridBagConstraints.PAGE_START;
 		gbc_userList.insets	= new Insets(space, space, space, space);
 
-		changeChatWindowColors(Settings.getInstance().getCurrentTheme());
+		changeChatWindowColors(Settings.getInstance().getThemes().get(Settings.getInstance().getCurrentTheme()));
 
 		contentPane.add(userList, gbc_userList);
 		contentPane.revalidate();
 
+		EventBus.getInstance().register(ThemeChangeEvent.class, (evt) -> changeChatWindowColors((Theme) evt.get()));
+
 		loadUsersAndChats();
 
 		if (client.isOnline()) startSyncThread(Config.getInstance().getSyncTimeout());
@@ -237,9 +240,7 @@ public class ChatWindow extends JFrame {
 	 *
 	 * @since Envoy v0.1-alpha
 	 */
-	public void changeChatWindowColors(String key) {
-		Theme theme = Settings.getInstance().getThemes().get(key);
-
+	private void changeChatWindowColors(Theme theme) {
 		// contentPane
 		contentPane.setBackground(theme.getBackgroundColor());
 		contentPane.setForeground(theme.getUserNameColor());
diff --git a/src/main/java/envoy/client/ui/SettingsScreen.java b/src/main/java/envoy/client/ui/SettingsScreen.java
index 161365d..fc0ebda 100644
--- a/src/main/java/envoy/client/ui/SettingsScreen.java
+++ b/src/main/java/envoy/client/ui/SettingsScreen.java
@@ -27,14 +27,16 @@ import javax.swing.ListSelectionModel;
 
 import envoy.client.LocalDB;
 import envoy.client.Settings;
+import envoy.client.event.EventBus;
+import envoy.client.event.ThemeChangeEvent;
 
 /**
  * This class provides the GUI to change the user specific settings.
- * 
+ *
  * Project: <strong>envoy-client</strong><br>
  * File: <strong>SettingsScreen.java</strong><br>
  * Created: <strong>31 Oct 2019</strong><br>
- * 
+ *
  * @author Leon Hofmeister
  * @author Maximilian K&auml;fer
  * @author Kai S. K. Engelbart
@@ -45,12 +47,12 @@ public class SettingsScreen extends JDialog {
 	private final JPanel		contentPanel		= new JPanel();
 
 	private DefaultListModel<String>	optionsListModel	= new DefaultListModel<>();
-	private final JList<String>			options				= new JList<String>();
+	private final JList<String>			options				= new JList<>();
 	private JPanel						buttonPane			= new JPanel();
 
 	private JPanel				themeContent	= new JPanel();
 	private String[]			themeArray		= Settings.getInstance().getThemes().keySet().toArray(new String[0]);
-	private JComboBox<String>	themes			= new JComboBox<String>(themeArray);
+	private JComboBox<String>	themes			= new JComboBox<>(themeArray);
 
 	private GridBagConstraints gbc_themeContent = new GridBagConstraints();
 
@@ -63,8 +65,7 @@ public class SettingsScreen extends JDialog {
 	private JButton		cancelButton	= new JButton("Cancel");
 	private static int	space			= 5;
 
-	private boolean	colorChanged	= false;
-	private Theme	temporaryTheme;
+	private Theme temporaryTheme;
 
 	private static final Logger logger = Logger.getLogger(LocalDB.class.getSimpleName());
 
@@ -77,7 +78,7 @@ public class SettingsScreen extends JDialog {
 
 	/**
 	 * Opens the settings screen.<br>
-	 * 
+	 *
 	 * @since Envoy v0.1-alpha
 	 */
 	public static void open() {
@@ -89,7 +90,7 @@ public class SettingsScreen extends JDialog {
 
 	/**
 	 * Builds the settings screen.
-	 * 
+	 *
 	 * @since Envoy v0.1-alpha
 	 */
 	private SettingsScreen() {
@@ -296,9 +297,10 @@ public class SettingsScreen extends JDialog {
 						Settings.getInstance().setCurrentTheme(selectedTheme.getThemeName());
 						System.out.println(selectedTheme.getThemeName());
 
-						changeSettingsScreenColors(Settings.getInstance().getCurrentTheme());
-						updateColorVariables(Settings.getInstance().getCurrentTheme());
-
+						final Theme currentTheme = Settings.getInstance().getThemes().get(Settings.getInstance().getCurrentTheme());
+						changeSettingsScreenColors(currentTheme);
+						updateColorVariables(currentTheme);
+						EventBus.getInstance().dispatch(new ThemeChangeEvent(currentTheme));
 						Settings.getInstance().save();
 
 						revalidate();
@@ -310,11 +312,10 @@ public class SettingsScreen extends JDialog {
 				});
 			}
 		}
-		changeSettingsScreenColors(Settings.getInstance().getCurrentTheme());
+		changeSettingsScreenColors(Settings.getInstance().getThemes().get(Settings.getInstance().getCurrentTheme()));
 	}
 
-	private void changeSettingsScreenColors(String key) {
-		Theme theme = Settings.getInstance().getThemes().get(key);
+	private void changeSettingsScreenColors(Theme theme) {
 		// whole JDialog
 		setBackground(theme.getBackgroundColor());
 		// contentPanel
@@ -345,19 +346,8 @@ public class SettingsScreen extends JDialog {
 
 	}
 
-	private void updateColorVariables(String key) {
-		Theme theme = Settings.getInstance().getThemes().get(key);
-
-		temporaryTheme = new Theme("temporaryTheme",
-				Settings.getInstance().getThemes().get(Settings.getInstance().getCurrentTheme()).getBackgroundColor(),
-				Settings.getInstance().getThemes().get(Settings.getInstance().getCurrentTheme()).getCellColor(),
-				Settings.getInstance().getThemes().get(Settings.getInstance().getCurrentTheme()).getInteractableForegroundColor(),
-				Settings.getInstance().getThemes().get(Settings.getInstance().getCurrentTheme()).getInteractableBackgroundColor(),
-				Settings.getInstance().getThemes().get(Settings.getInstance().getCurrentTheme()).getMessageColorChat(),
-				Settings.getInstance().getThemes().get(Settings.getInstance().getCurrentTheme()).getDateColorChat(),
-				Settings.getInstance().getThemes().get(Settings.getInstance().getCurrentTheme()).getSelectionColor(),
-				Settings.getInstance().getThemes().get(Settings.getInstance().getCurrentTheme()).getTypingMessageColor(),
-				Settings.getInstance().getThemes().get(Settings.getInstance().getCurrentTheme()).getUserNameColor());
+	private void updateColorVariables(Theme theme) {
+		temporaryTheme = new Theme("temporaryTheme", theme);
 
 		colorsPanel.removeAll();
 
@@ -462,7 +452,6 @@ public class SettingsScreen extends JDialog {
 					// TODO: When Theme changed in same settings screen, color variable doesnt
 					// update.
 					temporaryTheme.setColor(yIndex, newColor);
-					colorChanged = true;
 					createNewThemeButton.setEnabled(true);
 				}
 				button.setBackground(newColor);
@@ -481,8 +470,5 @@ public class SettingsScreen extends JDialog {
 		colorsPanel.add(panel);
 	}
 
-	private Color getInvertedColor(Color color) {
-		return new Color(255 - color.getRed(), 255 - color.getGreen(), 255 - color.getBlue());
-	}
-
+	private Color getInvertedColor(Color color) { return new Color(255 - color.getRed(), 255 - color.getGreen(), 255 - color.getBlue()); }
 }
diff --git a/src/main/java/envoy/client/ui/StatusTrayIcon.java b/src/main/java/envoy/client/ui/StatusTrayIcon.java
index 03380c2..4670377 100644
--- a/src/main/java/envoy/client/ui/StatusTrayIcon.java
+++ b/src/main/java/envoy/client/ui/StatusTrayIcon.java
@@ -11,12 +11,8 @@ import java.awt.TrayIcon.MessageType;
 import java.awt.Window;
 import java.awt.event.WindowAdapter;
 import java.awt.event.WindowEvent;
-import java.util.HashSet;
-import java.util.Set;
 
-import envoy.client.event.Event;
 import envoy.client.event.EventBus;
-import envoy.client.event.EventHandler;
 import envoy.client.event.MessageCreationEvent;
 import envoy.exception.EnvoyException;
 import envoy.schema.Message;
@@ -29,7 +25,7 @@ import envoy.schema.Message;
  * @author Kai S. K. Engelbart
  * @since Envoy v0.2-alpha
  */
-public class StatusTrayIcon implements EventHandler {
+public class StatusTrayIcon {
 
 	/**
 	 * The {@link TrayIcon} provided by the System Tray API for controlling the
@@ -85,7 +81,10 @@ public class StatusTrayIcon implements EventHandler {
 		trayIcon.addActionListener((evt) -> { focusTarget.setVisible(true); focusTarget.requestFocus(); });
 
 		// Start processing message events
-		EventBus.getInstance().register(this);
+		EventBus.getInstance().register(MessageCreationEvent.class, (evt) -> {
+			if (displayMessages)
+				trayIcon.displayMessage("New message received", ((MessageCreationEvent) evt).get().getContent().get(0).getText(), MessageType.INFO);
+		});
 	}
 
 	/**
@@ -102,31 +101,4 @@ public class StatusTrayIcon implements EventHandler {
 			throw new EnvoyException("Could not attach Envoy tray icon to system tray.", e);
 		}
 	}
-
-	/**
-	 * Notifies the user of a message by displaying a pop-up every time a new
-	 * message is received.
-	 *
-	 * @since Envoy v0.2-alpha
-	 */
-	@Override
-	public void handle(Event<?> event) {
-		System.out.println("Message received. Displaying message: " + displayMessages);
-		if (displayMessages)
-			trayIcon.displayMessage("New message received", ((MessageCreationEvent) event).get().getContent().get(0).getText(), MessageType.INFO);
-	}
-
-	/**
-	 * The {@link StatusTrayIcon} only reacts to {@link MessageCreationEvent}
-	 * instances which signify newly received messages.
-	 *
-	 * @return A set with the single element {@code MessageCreationEvent.class}
-	 * @since Envoy v0.2-alpha
-	 */
-	@Override
-	public Set<Class<? extends Event<?>>> supports() {
-		Set<Class<? extends Event<?>>> supportedEvents = new HashSet<>();
-		supportedEvents.add(MessageCreationEvent.class);
-		return supportedEvents;
-	}
 }