The assumption that cave art conventions reflect actual pigmentation is pretty shaky. The egyptian statue reference is just wrong - there's a long tradition of females being depicted as yellow or white versus red or brown for males. This probably has some basis in men engaging in more outdoors activity, but this art is definitely not a photo-realistic rendering. If you want a modern analogy, think the Simpsons! Here's some academic work that mentions the gender conventions:

http://www.mywire.com/a/Oxford-Encyclopedia-Ancient-Egypt/Ge...

I don't know anything about the other points in the article, but these errors make me doubt their accuracy.