"Saint Nelson" ( spit ), was a member of the Xhosa tribe and even lighter than this monster! HE WAS NOT OF MIXED RACE! And there are differences in color within the blacks in RSA and in other places, in Africa, as well. Just as there are differences in head shapes, facial features, height, build, etc.!
Not all whites have the same skin tones and that has NOTHING at all to do with having children with someone of another race.
Asians? Northern Chinese are much taller than those from the South and both look difference from peoples from other Oriental race nations!
Indians and Pakistanis ( once just one country ) is probably the one place with more racial differences, though they are all basically one race, than another place I can think of.