Add basic color scheme handling

Fix #59

src/widgets/chatwidgetheader.hpp

@@ -28,9 +28,6 @@ class ChatWidgetHeader : public BaseWidget
 public:
     explicit ChatWidgetHeader(ChatWidget *_chatWidget);
 
-    // Update palette from global color scheme
-    void updateColors();
-
     // Update channel text from chat widget
     void updateChannelText();
 
@@ -62,6 +59,8 @@ private:
     void leftButtonClicked();
     void rightButtonClicked();
 
+    virtual void refreshTheme() override;
+
 public slots:
     void menuMoveSplit();
     void menuReloadChannelEmotes();