How come native americans at the same latitude as Europe do not have white skin?

People indigenous to the warm Mediterranean have lighter skin then the Eskimos living in the Arctic.How come native americans at the same latitude as Europe do not have white skin?
Actually they are called indigenous people. Go check National Geographic to be exact.How come native americans at the same latitude as Europe do not have white skin?
Amerindians-Caucasians = different races.. the position on the globe doesn't count.. (is not from the sun)
genetic mutation is why