Why does EVERY race, except whites, have black hair and black hair only?

Yeah your wrong I dont know about Asians but Africans and African Americans can have every hair color to. You just dont notice much because its always a darker shade. I myself have redish brown hair. To an average caucasian person I have black hair. My cousin hair is all red and people always come up and her and ask if she died it when its her natural hair color. Very few of us can have blonde hair. Its rare but it happens. If you look at different African tribes some them have light brown hair to gold.