Plumage

Plumage, or feathering, is a layer of feathers that covers a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage differ between species and subspecies and may vary with sex and age classes. Within a few species, there can be different colour morphs. The placement of feathers on a bird is not haphazard but rather emerges in organised, overlapping rows... (Wikipedia)