Schemochrome

First, a blue pigment is known from birds (rhodoxanthin, a xanthophyll producing the blue of fruit pigeons, Ptilinopus; see Buckley 1982 : 61), although the blue of parrots is almost certainly not based on a pigment (biochrome), but rather is a schemochrome (structural color).

In some groups a schemochrome overlies a conspicuous biochrome, with spectacular effect.

The fine scales on the wings of some butterflies and the surface of scarab beetles produce schemochrome colours (Chapman, 1998a).