Structural effects contribute to the coloration of many animals. Whereas extremely complex structures have evolved, often coloration is due to the most simple structure, namely a thin film. Here we present a number of examples where thin film optics plays a prominent role, namely in insect wings and bird feathers. Most butterfly wing scales have a lower lamina that prominently determines the color. Damselfly wings with protrusions have reduced thin film reflections. A limited stack of multilayers features also distinct thin film properties, as is shown for feather barbules of the bird of paradise, Lawes’ parotia. A simple method to derive the thickness of the wing structures is described.

This article originally appeared in Materials Today: Proceedings 1, Supplement, 2014, Pages 109-121