xanthochroism

Century Dictionary and Cyclopedia

1. n. In ornithology, the fact or condition of having abnormally yellow feathers. It occurs most frequently in cases where feathers are normally green, red, or orange, and is often seen in parrots and tanagers.

GNU Webster's 1913

1. n. Abnormal coloration of feathers in which yellow replaces the normal color, as in certain parrots. It is commonly due to lack of the dark pigment which with yellow forms green.