fix: multiple UI fixes

- Leave message UI
- Better support for dark mode

Change-Id: I8ee94aa1a973fcb030be695573d6d1461e730e22
diff --git a/src/RingWindowController.mm b/src/RingWindowController.mm
index 5d3f4dc..816e8fc 100644
--- a/src/RingWindowController.mm
+++ b/src/RingWindowController.mm
@@ -430,7 +430,7 @@
                 CGContextAddRect(ctx, rectDraw);
                 CGContextFillPath(ctx);
             } else {
-                CGContextSetFillColorWithColor(ctx, [NSColor windowBackgroundColor].CGColor);
+                CGContextSetFillColorWithColor(ctx, [NSColor clearColor].CGColor);
                 rectDraw.origin = CGPointMake((j + qr_margin) * zoom,(i + qr_margin) * zoom);
                 CGContextAddRect(ctx, rectDraw);
                 CGContextFillPath(ctx);