Dichroic glass:

Dichroic glass contains multiple micro-layers of metals or oxides which gives it the optical properties that transmit or reflect light in a multitude of colors.  The angle of light shift the colors.  Dichroic glass actually dates back to at least 4th century though modern dichroic is a result of materials research by NASA.

For a wall piece?

Fired round plate 9inches

Plate in it's frame