Colorize Callisto and Ganymede map
Bj枚rn J贸nsson provides on his website a collection of color map for many body of the solar system. Amount them Callisto and Ganymede:
In both case, a mask is provided to discard the fictive part of the data.
It is possible to extract the color layer of the map to overlap it on top of the black and white images that we are currently using (this was done for Europa in the past).