diff --git a/lcl/interfaces/cocoa/cocoagdiobjects.pas b/lcl/interfaces/cocoa/cocoagdiobjects.pas
index e463c2afea..41f9032e78 100644
--- a/lcl/interfaces/cocoa/cocoagdiobjects.pas
+++ b/lcl/interfaces/cocoa/cocoagdiobjects.pas
@@ -1038,10 +1038,23 @@ begin
 end;
 
 procedure TCocoaContext.SetBkColor(AValue: TColor);
+var
+  SysBrush: TCocoaBrush;
+  Color: NSColor;
 begin
-  AValue := TColor(ColorToRGB(AValue));
-  FBkColor := AValue;
-  FBkBrush.SetColor(AValue, BkMode = OPAQUE);
+  if IsSysColor(AValue) then
+  begin
+    SysBrush := TCocoaBrush(CocoaWidgetSet.GetSysColorBrush(SysColorToSysColorIndex(AValue)));
+    Color := TCocoaBrush(SysBrush).Color;
+    FBkColor := NSColorToColorRef(Color);
+    FBkBrush.Color := Color;
+    FBkBrush.Solid := BkMode = OPAQUE;
+  end
+  else
+  begin
+    FBkColor := AValue;
+    FBkBrush.SetColor(AValue, BkMode = OPAQUE);
+  end;
 end;
 
 procedure TCocoaContext.SetBkMode(AValue: Integer);
diff --git a/lcl/interfaces/cocoa/cocoautils.pas b/lcl/interfaces/cocoa/cocoautils.pas
index d7d1071938..b41362dd61 100644
--- a/lcl/interfaces/cocoa/cocoautils.pas
+++ b/lcl/interfaces/cocoa/cocoautils.pas
@@ -59,7 +59,10 @@ function GetNSControlValue(c: NSControl): String; inline;
 
 procedure ColorToRGBFloat(cl: TColorRef; var r,g,b: Single); inline;
 function RGBToColorFloat(r,g,b: Single): TColorRef; inline;
+// extract ColorRef from NSColor in RGB colorspace
 function NSColorToRGB(const Color: NSColor): TColorRef; inline;
+// extract ColorRef from any NSColor
+function NSColorToColorRef(const Color: NSColor): TColorRef;
 function ColorToNSColor(const Color: TColorRef): NSColor; inline;
 
 implementation
@@ -85,6 +88,66 @@ begin
     Result := RGBToColorFloat(redComponent, greenComponent, blueComponent);
 end;
 
+function NSColorToColorRef(const Color: NSColor): TColorRef;
+
+function AverageColor(Color1, Color2: TColorRef): TColorRef; inline;
+  begin
+    if Color1 = Color2 then
+      Result := Color1
+    else
+      Result :=
+        (((Color1 and $FF) + (Color2 and $FF)) shr 1) and $FF or
+        (((((Color1 shr 8) and $FF) + ((Color2 shr 8) and $FF)) shr 1) and $FF) shl 8 or
+        (((((Color1 shr 16) and $FF) + ((Color2 shr 16) and $FF)) shr 1) and $FF) shl 16;
+  end;
+
+var
+  LocalPool: NSAutoReleasePool;
+  RGBColor, PatternColor: NSColor;
+  ImageRep: NSImageRep;
+  x, y: Integer;
+begin
+  LocalPool := NSAutoReleasePool.alloc.init;
+  RGBColor := Color.colorUsingColorSpaceName(NSCalibratedRGBColorSpace);
+  // if color is a pattern it can't be converted as is to a solid color value
+  if RGBColor = nil then
+  begin
+    PatternColor := Color.colorUsingColorSpaceName(NSPatternColorSpace);
+    if PatternColor = nil then
+      Result := 0
+    else
+    begin
+      // compute an average color of the top left 2x2 rectangle
+      ImageRep := PatternColor.patternImage.bestRepresentationForRect_context_hints(RectToNSRect(Types.Rect(0, 0, 1, 1)), nil, nil);
+      if (ImageRep = nil) or not ImageRep.isKindOfClass(NSBitmapImageRep) then
+        Result := 0
+      else
+      begin
+        for y := 0 to ImageRep.pixelsHigh - 1 do
+          for x := 0 to ImageRep.pixelsWide - 1 do
+          begin
+            RGBColor := NSBitmapImageRep(ImageRep).colorAtX_y(x, y).colorUsingColorSpaceName(NSCalibratedRGBColorSpace);
+            if Assigned(RGBColor) then
+            begin
+              if (x = 0) and (y = 0) then
+                Result := NSColorToRGB(RGBColor)
+              else
+                Result := AverageColor(Result, NSColorToRGB(RGBColor))
+            end
+            else
+            begin
+              Result := 0;
+              break;
+            end
+          end;
+      end;
+    end;
+  end
+  else
+    Result := NSColorToRGB(RGBColor);
+  LocalPool.release;
+end;
+
 function ColorToNSColor(const Color: TColorRef): NSColor; inline;
 begin
   Result := NSColor.colorWithCalibratedRed_green_blue_alpha(
diff --git a/lcl/interfaces/cocoa/cocoawinapi.inc b/lcl/interfaces/cocoa/cocoawinapi.inc
index 901235e9d9..c0d5fb18b0 100644
--- a/lcl/interfaces/cocoa/cocoawinapi.inc
+++ b/lcl/interfaces/cocoa/cocoawinapi.inc
@@ -1047,23 +1047,8 @@ begin
 end;
 
 function TCocoaWidgetSet.GetSysColor(nIndex: Integer): DWORD;
-
-  function AverageColor(Color1, Color2: TColorRef): TColorRef; inline;
-  begin
-    if Color1 = Color2 then
-      Result := Color1
-    else
-      Result :=
-        (((Color1 and $FF) + (Color2 and $FF)) shr 1) and $FF or
-        (((((Color1 shr 8) and $FF) + ((Color2 shr 8) and $FF)) shr 1) and $FF) shl 8 or
-        (((((Color1 shr 16) and $FF) + ((Color2 shr 16) and $FF)) shr 1) and $FF) shl 16;
-  end;
-
 var
-  LocalPool: NSAutoReleasePool;
-  Color, RGBColor, PatternColor: NSColor;
-  ImageRep: NSImageRep;
-  x, y: Integer;
+  Color: NSColor;
   SysBrush: HBrush;
 begin
   // 1. get the system brush - it has a NSColor reference
@@ -1077,47 +1062,7 @@ begin
   Color := TCocoaBrush(SysBrush).Color;
 
   if Assigned(Color) then
-  begin
-    LocalPool := NSAutoReleasePool.alloc.init;
-    RGBColor := Color.colorUsingColorSpaceName(NSCalibratedRGBColorSpace);
-    // if color is a pattern it can't be converted as is to a solid color value
-    if RGBColor = nil then
-    begin
-      PatternColor := Color.colorUsingColorSpaceName(NSPatternColorSpace);
-      if PatternColor = nil then
-        Result := 0
-      else
-      begin
-        // compute an average color of the top left 2x2 rectangle
-        ImageRep := PatternColor.patternImage.bestRepresentationForRect_context_hints(RectToNSRect(Types.Rect(0, 0, 1, 1)), nil, nil);
-        if (ImageRep = nil) or not ImageRep.isKindOfClass(NSBitmapImageRep) then
-          Result := 0
-        else
-        begin
-          for y := 0 to ImageRep.pixelsHigh - 1 do
-            for x := 0 to ImageRep.pixelsWide - 1 do
-            begin
-              RGBColor := NSBitmapImageRep(ImageRep).colorAtX_y(x, y).colorUsingColorSpaceName(NSCalibratedRGBColorSpace);
-              if Assigned(RGBColor) then
-              begin
-                if (x = 0) and (y = 0) then
-                  Result := NSColorToRGB(RGBColor)
-                else
-                  Result := AverageColor(Result, NSColorToRGB(RGBColor))
-              end
-              else
-              begin
-                Result := 0;
-                break;
-              end
-            end;
-        end;
-      end;
-    end
-    else
-      Result := NSColorToRGB(RGBColor);
-    LocalPool.release;
-  end
+    Result := NSColorToColorRef(Color)
   else
     Result := 0;
 end;