Bob has been asked; "Why so many different colors?"  He responds; "When I see a creature, whether its a sea turtle or a hippo, it's not just a few colors I see.  It takes sometimes a touch of this or that basic color mixed together (or even five or six colors mixed together) just to get the EDGE of the body of the animal, much less the rest of the image.  As light plays across the animal's skin it changes in color.  More colors are needed to accomplish and capture what I see there".