Get Color Indices
From PyMOLWiki
get_color_indices will retrieve the RGB values for colors.
print cmd.get_color_indices()
will retrieve the color indices
print cmd.get_color_tuple(index-number)
set_color color-name, [r,b,g]
will create a new color that will appear in the GUI list. From the open-source GUI you can use the "add" button in the color list viewer. In MacPyMOL, enter the new name into the MacPyMOL color editor window, set the RGBs, and then click Apply.
