Xanthochromism
A xanthochromistic and normal Argentine horned frog
Xanthochromism (also called xanthochroism or xanthism), from the Greek xanthos (ξανθός) "yellow" and chroma (χρώμα) "color", is an unusually yellow pigmentation in an animal. It is often associated with the lack of usual red pigmentation and its replacement with yellow. The cause is usually genetic but may also be related to the animal's diet. The opposite of xanthochromism, a deficiency in or complete absence of yellow pigment, is known as axanthism.