The Collaborative International Dictionary
Erythrochroism
Erythrochroism \E*ryth"ro*chro*ism\, n. [Gr. 'eryqro`s red + ? color.] (Zo["o]l.) An unusual redness, esp. in the plumage of birds, or hair of mammals, independently of age, sex, or season.
Wiktionary
erythrochroism
n. (context zoology archaic rare English) An unusual redness, as in hair or plumage.