I’m Caucasian. My skin is not pure white—that would be weird—but I can make my relatively whitish skin turn a bit orange when I drink a lot of carrot juice. Similarly, a male cardinal has to eat a lot of the right seeds and fruits to keep its feathers red all year. The same class of chemicals that make my skin turn orange, carotenoids, make the red in the cardinal’s feathers. Carotenoids are a class of pigments that gets its name from carrots. The red in the feathers last for the life of the feathers, about a year; and the orange in my skin, thankfully, only lasts a day.
This feather is from an eclectus parrot, a bird that also gets its red color from the food it eats.