gcvalues.foreground = BlackPixel (display, DefaultScreen (display));
gcvalues.background = WhitePixel (display, DefaultScreen (display));
gcvalues.graphics_exposures = False;
gcvalues.foreground = BlackPixel (display, DefaultScreen (display));
gcvalues.background = WhitePixel (display, DefaultScreen (display));
gcvalues.graphics_exposures = False;