+ Screen *screen = DefaultScreenOfDisplay (dpy);
+ Visual *visual = DefaultVisualOfScreen (screen);
+ Window window = RootWindowOfScreen (screen);
+ int vclass = get_visual_class (dpy, visual);
+
+ ncolors = CellsOfScreen (screen);
+
+ /* If this is a colormap on a mono visual, or one with insanely many
+ color cells, bug out. */