Flamingos are actually white.

They get their pink colour from their food.  Many plants produce natural red, yellow or orange pigments, called carotenoids. Carotenoids give carrots their orange colour or turn ripe tomatoes red. They are also found in the microscopic algae that brine shrimp eat. As a flamingo eats algae and brine shrimp, its body metabolizes the pigments — turning its feathers pink.