[ftarquisa]

sure thing. I start with pics from google or the alike in RGB format



second, use light, contrast and color balance (or whatever suits you best) to minimize color differences among pics put together, and, then, convert into Indexed color format, selecting a number of desired basic colors, you can even get them from the very pics (do several trials until you get what you want). After conversion do convert it back into RGB.

now you can do many more things: separate colors in layers, erease small spots for evey layer, try enlarging surviving spots, no limits...