dichroic

Literally "two colors".   Dichroic glass changes color as it is moved in the light.

Dichroic glass is manufactured by fusing thin metalic films to the surface of the glass.  These films allow the glass to transmit different colors than they reflect.

Dichroic glass is especially popular with glass kilnforming artists making jewelry.
 

The image on the left shows a piece of dichroic
coated glass lit from behind.  The image on the right
is the same glass with the light in front of the glass.