What is Dichroic Glass? Dichroic (pronounced “dye-crow-ick”) glass, commonly called dichro for short, literally means “two coloured.” It is derived from the Greek words “di” for two, and “chroma” for colour. It was thus named because of its fantastic multicoloured and reflective properties. When you look at this glass, it appears to have more than one colour at the same time, especially when viewed with different lighting. This reflective phenomenon is known as thin-film physics, which is also why you see swirling rainbow patterns in a soap bubble, floating colours from oil on water and the dramatic colours of dragonfly wings.