There are many field guides to birds of the United States. Refer to one if you want to know which colours go exactly where on these thirty-three precisely drawn illustrations. Or create your own fantastic ornithological kingdom by using the brightest shades and patterns you can imagine. It's almost impossible to improve upon the natural colours of the abstract-art-themed wood duck or the well-named painted bunting, but there's no reason not to give the American robin a makeover.