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 is a thing about some surfaces. If a surface looks like its colour changes as the light moves, then it is iridescent.

Iridescence in soap bubbles
The iridescent exoskeleton of a golden stag beetle

There are many iridescent things in nature. Soap bubbles, butterfly wings and sea shells, and some minerals are iridescent. They have tiny structures that affect the light.

The physical process which causes iridescence is usually interference.