A single enzyme can alter the vibrant colors in parrot plumage
Transforming an aldehyde into a carboxyl group can fine-tune feathers from red to yellow

A new study shows levels of an enzyme called ALDH3A2 can fine-tune parrot pigments to make their feathers — like the ones on this dusky lory (Pseudeos fuscata) — more yellow or red.
Tim Felce/wikimedia commons (CC BY-SA 2.0)