Flamingos get their pink color from the food they eat. Flamingos eat algae, shrimp, and other small organisms that are full of carotenoids. These carotenoids are like natural food coloring. When flamingos eat these foods, the carotenoids are stored in their feathers, which turn them pink.
If a flamingo doesn't eat enough carotenoids, its feathers will turn white. If a flamingo eats a lot of blue-green algae, its feathers will turn blue or green.