I snapped a photo of this cool insect on a recent hike. Here’s the thing: This insect only has one pigment in its body. Black. So, how does it make such amazing colors?

The amazing rainbow hues you see aren’t due to pigment—they are due to structure, thin films and fine lines that create colors like the rainbow hues from a soap bubble or the reflection from a compact disc. The key to identifying structural color? The color you see depends on your viewing angle, and the angle of where the light comes from.

Turns out that when things fossilize, pigments aren’t preserved. But structure can be. So there are fossilized insects that still show the colors the living creatures had.

The next time you are in nature, watch for examples of metallic, hue-shifting color in flies, beetles, and other insects. It’s a pretty widespread phenomenon!