Dichroic glass is a dazzler, with the ability to show off two different colors, and from which the name comes: Di(two) Chroic(Color). A thin coating of metal is applied to glass in a vacuum chamber and involving lasers. The process started out as a project of NASA for protecting equipment on spacecraft, and coatings on astronaut helmets. In a poetic turn, a NASA Technical Report refers to it as Chameleon Glass. The coating interferes with the normal transmission of light, and two colors emerge, one from transmitted light and one from reflected light.
My interpretation of this effect in my Helix Nebula Mandala is that the dichroic glass in the center above mostly is transmitted green, whereas the photo below, taken at a different angle, shows reflected magenta.
Coatings by Sandberg arose from a coatings engineer observing Murray Schwartz, engineer and artist, taking out of spec dichroic mirrors from the trash to make sculpture. Talking with Schwartz, Jerry Sandberg realized there were artists who would adore working with dichroic glass, and he started his coatings company specifically for the art market.