--- src/interface.c	2005-06-07 18:15:24.000000000 +0200
+++ src/interface_rgba.c	2008-03-24 14:12:42.000000000 +0100
@@ -91,6 +91,15 @@
 	appdata->window_main = gtk_window_new (GTK_WINDOW_TOPLEVEL);
 	gtk_window_set_title (GTK_WINDOW (appdata->window_main),
 			      _("GtkPerf"));
+
+	GdkScreen *screen = gtk_widget_get_screen(appdata->window_main);
+	GdkColormap *colormap = gdk_screen_get_rgba_colormap (screen);
+
+	if (colormap && gdk_screen_is_composited (screen))
+	{
+		gtk_widget_set_default_colormap(colormap);
+	}
+
 	gtk_window_set_default_size (GTK_WINDOW (appdata->window_main), 500,
 				     300);
 	gtk_widget_show(appdata->window_main);