Carotenoid

A flamingo's pink feathers aren't its natural color. Flamingos hatch gray; they turn pink as carotenoid pigments from the brine shrimp and algae they eat build up in their bodies. Without these pigments in their diet, their feathers fade back toward a pale white.

Salmon flesh isn't naturally orange. Salmon are actually white-fleshed fish; their pink-orange color comes from astaxanthin, a carotenoid pigment they absorb by eating krill and shrimp. Farmed salmon whose feed lacks this pigment stay a grayish-white.