It’s claimed the mutation on the SLC24A5 gene that gives Europeans very pale skin dates to between 6,000 and 12,000 years old. This would give the first immigrants into Europe an Asian tan colour skin. However, the dating of at least two variants of the European red hair gene go back to about 80,000 years.
“Both African and non-African data suggest that the time to the most recent common ancestor is ~1 million years and that the age of the global 314 variant is 650,00 years. On this time scale, ages for the Eurasian-distributed Val60Leu, Val92Met, and Arg163Gln variants are 250,000-100,000 years; the ages for African silent variants—Leu106Leu, Cys273Cys, and Phe300Phe—are 100,000-40,000 years. For the European red hair-associated Arg151cys and Arg160Trp variants, we estimate an age of ~80,000 years; for Asp294His, and Ser316Ser, we estimate an age of <= 30,000 years. “ (Harding et al, 2000, p. 1357 )
The red hair genes generally produce a somewhat lighter skin tone, even if you aren’t homogeneous for ginger hair genes (ie, red haired). I should know, I have one pale ginger gene from Granny, and I’m porcelain skinned and burn very easily, even with the dark hair. Red haired individuals are a lot lighter skinned and don’t tan, and prone to sunburn. Alos, genes that cause lighter eye colours also lighten skin colour.
Leaving aside the Neanderthal date of this gene, this would make the first Europeans pretty much the same skin tone wise as modern ones, as the red hair MC1R mutations affect skin as well as hair colour, almost like a mild form of albinism. This would have meant there probably wasn’t much difference between Cro Magnon and Modern European skin tone.
My hypothesis is, that the recent light skin colour mutation is a recent improvement on the mutations to the MC1R that cause ginger hair, as they allow skin light enough to allow vitamin D synthesis, but it also allows the carrier to tan to a limited degree, giving some UV protection as well. This could mean that the MC1R ginger hair genes are slowly being replaced by the light skin gene, and ’gingerness’ was probably carried by the majority of early Europeans. The red hair mutation is fine if the base skin colour is an Asian tan, but add it to European pale skin and you’ve got a recipe for sunburn. I expect the frequency of red heads has been decreasing ever since the skin lightening mutation came along.
So different gene, similar effect on skin tone.
As an after thought, I’ve found a picture of an Indian boy with Caucasian features and light coloured eyes. He’s probably a good approximation of what the first Europeans looked like, about 35,000 years ago. Not including the shirt.