DICHROIC refers to one or more mono-molecular layers of "rare earth"
material that is deposited on glass through a process of electron discharge coating in a vacuum chamber. The brilliant dual color effect is produced by the spectral shift of light at the interface of the glass and the coating.
Sometimes multiple layers are "sputtered" on for more complex spectral shifts. This "surface effect" is similar to the way color in bird feathers is produced. Dichroic glass is categorized by both the transmitted and the reflected colors. A computer monitor is an example of "transmitted" color and a painting on the wall is an example of "reflective" color.