Iridescence

property in which fine colors, changeable with the angle of view or angle of illumination, are produced on a surface by the interference of light that is reflected from both the front and back of a thin film
Iridescence in soap bubbles
The iridescent exoskeleton of a golden stag beetle

Iridescence is a physical property of some surfaces. Their colour appears to change as the angle of view or illumination changes.

Examples of natural iridescence are common. It can be seen in soap bubbles, butterfly wings and sea shells, and certain minerals. These are structural colours caused by microstructures which interfere with light.

The physical process which causes iridescence is usually interference.