The lighting and shading simulation uses a dithering method to simulate true RGB colors on X11. GPHIGS allocates a dithering colormap from index 16 to 140 ( 5*5*5 values) in the colormap of each workstation. This table may be modified or suppressed by including a directive in the configuration file.
%di no suppresses the dithering table allocation
%di yes 8 2 creates a dithering table starting at index number 8 and containing 2*2*2 elements.