In a Nutshell:

This movement is the use of a a spectrum effect which is distorted as it transitions over surfaces and objects. The iridescent effect is characterized by the appearance of changing color.

Iridescence is the phenomenon of certain surfaces that appear to change color as the angle of view or the angle of illumination changes. It is also termed in the fashion world as ‘holographic’ and is used heavily in current women’s fashion but is emerging across many mediums. As seen below.