Ancient Lybians seem to have had a higher percentage of light pigmented individuals and if considering that modern Berbers have significant later Near Eastern and even Subsaharan admixture, practically all of them, the high incidence of light skin, but even light eye and hair color among them is even more telling. There are people which attributed this to Greeks, Romans and Germanics, but the ancient Egyptian sources tell us they looked not just similar then, but were even lighter.

So the fact remains that the Berbers, and even some Guanches, had at least significant amounts of light coloration allels, even if they might have been never the majority. So the idea of light skin pigmentation being spread by late incomers is wrong, it was present among E1b1b dominated North Africans already, latest in Neolithic times.