Sims skin colors carry through in future generations too, as I also love all differentskin colors, although I have to admit I am not much with Purple or bright Red sims - hehehe - but I have one family I play off and on since the Sims came out - the Bachelors from the base game where Michael Bachelor married my version of Dina Calienti that I made her parents as children - her dad was the product of an Italian looking dad and her mother had light green skin so I could add in the slien of her family. Granted in my version of the Calienti's they ended up with several sibblings before I finally got twins to name Nina and Dina. But eventually I got her grown and married to Michael just before he turned elder. Their third child was a girl who indeed had her mothers greenish skin, so it was cool to see the skin type carry like that. That girl ended up with a greatgrandson before there was another with the greenish tone and each one was not the same color as Dina's Mother, but variations of the shade. I do know the colors got better mixed and more realistic after Ambitions came out, though.
Of course the way I play now and the way I played then have changed. i used to play with carefully manipulating and planning certain sims to marry other sims, etc - now I just let my sims pick who they want to marry 98 times out of a 100. Only rarely do I step in there and steer the relationship - and it surely has never a thing to do with Sims skin color. Sims are color blind - and we should all take a lesson that color means nothing. In my game there is one race - the human pixel one and just like mammals, sims come in a variety of skin or fur colors. There is no room on this planet for people who judge other people for their color of their fur. Do you people who judge things on color also all just pick all white dogs, cats, horses, and whatever pets you add to your family?
Take a lesson from your sims, they don't see skin color period.