Way back, I came across some free files for V2, at RDNA, which modified texturemaps by changing the base Diffuse Color. I'll have to dig them out and see how the idea works for V4. As I recall, the results were OK for the smaller changes, sort of within the European range of skin tones. It's something that might be useful for V4 at the moment, with so few texture sets out there. This looks like the file. They're partial poses, just changing a part of the materials settings, and I doubt there's an easy way of translating them. I modified some for V3 by hand-editing, changine material names and duplicating the block a few times. Look for the Beach Babes set near the end of the freestuff section, on this page.