opalescent

Opalescent materials display a fascinating range of colours, which arises from the way they scatter light when it enters them. This scattering produces a spectral shimmer or iridescence known as opalescence.

To achieve this effect, the material must have a certain translucency or opacity so that light can enter and be reflected. This creates a multi-layered, iridescent colouring that can vary depending on the viewing angle and the incidence of light.