Britannica
Sources used in this answer
Why does removing yellow pigment from a green feather leave it blue?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
coloration
The anole changes color in response to its stress level.
The premise that removing yellow pigment from a green feather leaves it blue is correct. In bird coloration, green is typically not the result of a green pigment. Instead, most green feathers are produced by the combination of a structural blue color and a yellow pigment.1
Blue colors in feathers are structural, created by a thin, porous layer of keratin that overlies a dark melanin base. When a yellow carotenoid pigment is present in the feather, it filters the light reflecting off this structural blue layer, resulting in the appearance of green. Therefore, if the yellow pigment is removed, the underlying structural blue color is revealed.1