Carotenoids are yellow-to-orange pigments that lend color of certain flowers, fruit, vegetables, corn kernels, fall leaves, salmon, shellfish, egg yolks, and feathers of various birds. Carotenoids are also internally in many organisms. Over 1100 naturally occurring carotenoids have been described. Most animals cannot produce their own carotenoids. They rely on a dietary supply of carotenoids with roles in essential functions.