Evolutionary biologist Armand Leroi examines the processes that affect skin colour and what happens when they go wrong. Piebalds, with their patches of black and white skin, and albinos from all races demonstrate the effect of turning on and off genes that control pigmentation. South African housewife Rita Hoefling went to bed white and woke up black. Leroi also meets Mexican circus performer Jesus "Chuy" Aceves, whose face is covered in thick hair, and the most beautiful woman in the world.
