Another question from those crazy creationists.
Evolutionist: What colour was the skin of the first human?
So why are some races made different varieties of colours? Is there a reason for this?
Yes, we call it evolution.
Homo sapiens originated in east Africa around 200,000 years ago. By about 70,000 years ago the human population is estimated to be around 2000 to 5000 individuals. From those about 150 people crossed the Red Sea and went on to inhabit the rest of the world, Asians branched first, settling in southern Asia by about 60,000 years ago, later reaching east Asia by about 30,000 years ago, Europeans branched off the older Asian populations settling in Europe around 50,000 years ago, with members from northern and eastern Asia settling in the Americas between 30,000 and 10,000 years ago.
Because the populations were isolated, any new genetic information couldn't be exchanged between them, resulting in the variation we see today. If we were isolated for a couple of million years longer the changes would have gradually built up until we were all different species.