Why you'd want to do that, I don't know, but someone asked me how to turn the window background yellow. Since the window has a contentView NSView in it, this adds a category on it that draws the background with a transparent yellow. You also get the pinstripe effects. Just put this code anywhere.@implementation NSView (BWYellowView) - (void) drawRect: (NSRect) rect { NSColor *transparentYellow; rect = [self bounds]; transparentYellow = [NSColor colorWithCalibratedRed: 1.0 green: 1.0 blue: 0.0 alpha: 0.333]; [transparentYellow set]; [NSBezierPath fillRect: rect]; } // rect @end // BWYellowViewI have no idea how you colorize the titlebar.