This picture demonstrates the wide range of colors seen - even in relatively flat light - on this still not at peak season bird along with the wirey, almost hair-like structure known as a "beard". The feathers overlap and intertwine in an almost flawless manner.
The color we see in bird feathers comes from the pigmentation of the feather, the structure of the feather, or a combination of the two. Some birds acquire pigments called carotenoids through their diet, while others like melanin are naturally occurring in the skin and feathers.
Iridescence, however, comes from structural coloration. A keratin protein in the feather acts as a prism, refracting shorter light waves to show blues, violets, purples, and greens. But birds are also able to mix the carotenoid color of the feather with iridescence, resulting in even a wider array of colors.