alloc_color_cells/5 and alloc_contig_color_cells/5

     alloc_color_cells(+Colormapable, +NColors, -Pixels,
                       +NPlanes, -Planes)
     alloc_contig_color_cells(+Colormapable, +NColors, -Pixels,
                             +NPlanes, -Planes)
     

Pixels is a list of NColors pixel values (integers), and Planes is a list of NPlanes plane masks that have been allocated from the colormap associated with Colormapable. Colormapable defaults to the default colormap of the default screen. For alloc_contig_color_cells/5, Pixels are sequential numbers.