Dark mode support

Centralized all colors, tweaked application paletter in darkmode to make it darker.

pglab/codeeditor/GutterPainter.h

@@ -1,5 +1,6 @@
 #include <QPainter>
 #include <QTextBlock>
+#include "util/Colors.h"
 
 #pragma once
 
@@ -13,10 +14,13 @@ public:
 
     void Paint();
 private:
+
     CodeEditor *editor;
     QPainter painter;
     QPaintEvent *event;
     QFontMetrics fontMetrics;
+    const ColorTheme &colorTheme;
+
 
     struct LoopState {
         CodeEditor *editor;