Twins can be born where one is black and the other is white.
Having a black and white twin is not a big deal. Identical twins develop from one zygote that splits and forms two embryos. Fraternal twins are two eggs that have been fertilized by separate sperm. An assortment of genes go into the egg and sperm to get skin color. Geneticists say that racial differences involve many genes and are more complex in determining looks than those for eye color. Each year, 12,000 sets of twins are born in Britain out of these, 385 of them are black or mixed race.