Actually, flamingos are not pink. They are born with grey feathers, which gradually turn pink in the wild because of a natural pink dye called canthaxanthin that exist in carotene protein they obtain from their diet of brine shrimp and blue-green algae.
The bird’s digestive system extracts pigment from carotenoid-containing food and it eventually dissolves in fats. The fats are then deposited in new feathers as they grow, and the flamingo’s color slowly shifts to pink.
Flamingos’ colors can range from pale pink to crimson, depending on the amount of pigment present in the bird ‘s diet.