TexturesThis is how masses could look with noisy random textures on them. perlin noise would be a method to generate them, and for instance overlay them in real time, shifting as the mass moves. Here is a GIMP draft:
Well. In my oppinion those random textures look pretty boring. Though they add extra-noise to the screen, they do not contribute to the game in any way. I find height dependent color is much more interesting, since you usually can only guess the height of a mass. With those textures in motion, it would look much nicer, though. But I expect it to be quite slow.