Hair color tends to come up pretty organically when talking about heredity and genetic traits. Blonde hair in people of European descent is a result of a the interactions of a combination of genes, but the blonde afros of Melanesians appears to be the result of a single mutation of a single gene.
Switching one “letter” of genetic code-replacing a “C” with a “T”-meant the difference between dark hair and blond hair.
— Loury (2012): The Origin of Blond Afros in Melanesia in Science