Axanthism

The mutation affects the amount of xanthophores and carotenoid vesicles, sometimes causing them to be completely absent.

[1] Erythrophores and iridophores, which are responsible for red coloration and light reflecting pigments respectively, may also be affected.

Green coloration in animals is caused by iridiphores reflecting blue wavelengths of light back through the carotenoids in the xanthophores.

[5] When iridophores are affected by axanthism, the animal typically becomes duller or darker in coloration due to a lesser amount of light reflected.

Axanthism can affect the camouflage and aposematic patterns of amphibians, making these individual stand out more or render their defenses useless.

An axanthic green frog ( Lithobates clamitans ). Axanthism is most common in species of Ranidae .
Yellow-collared lovebirds ( Agapornis personatus ) are a good example of the effects of axanthism. The feathers that would be normally green are blue, and the feathers that would be yellow are white.