This is done by prisms breaking sunlight into a rainbow, or Newton's Rings of color appearing on oil slicks. Peacocks and bluejays and blue morphos all get thei

This is done by prisms breaking sunlight into a rainbow, or Newton's Rings of color appearing on oil slicks. Peacocks and bluejays and blue morphos all get their color from notch filters applied to the Fourier transform. It's a pretty common effect, and frankly trivial. Lensless holographic focusing lenses on sea star exoskeletons are a bit less surprising... but only because they actually evolved, not because it could happen.