Flamingos are born grey and turn pink from their diet.

Flamingo chicks hatch with grey, downy feathers. Their signature pink or orange color develops gradually as they mature and feed on algae, brine shrimp, and other small organisms rich in pigments called carotenoids — the same class of pigments that make carrots orange.

A flamingo’s body metabolizes these carotenoids and deposits them in its feathers, skin, and even its egg yolks. Flamingos in captivity fed a diet lacking sufficient carotenoids will fade to a pale, washed-out color, which is why zoos supplement their food with pigment additives to keep them looking vividly pink.