--- a/widget/cocoa/nsCocoaWindow.mm
+++ b/widget/cocoa/nsCocoaWindow.mm
@@ -3412,17 +3412,17 @@ static const NSString* kStateCollectionB
 
 - (void)setTemporaryBackgroundColor
 {
   [super setBackgroundColor:[NSColor whiteColor]];
 }
 
 - (void)restoreBackgroundColor
 {
-  [super setBackgroundColor:mBackgroundColor];
+  [super setBackgroundColor:mColor];
 }
 
 - (void)setTitlebarNeedsDisplayInRect:(NSRect)aRect
 {
   [self setTitlebarNeedsDisplayInRect:aRect sync:NO];
 }
 
 - (void)setTitlebarNeedsDisplayInRect:(NSRect)aRect sync:(BOOL)aSync