A Prism is a lightsplitter, meaning he can take white light and split it into all colors. He also has to be a full spectrum polychrome. This is necessary to become a Prism, but not to be a lightsplitter, as the Blinder’s Knife can somehow confer and retract this ability. The Prism is a religious figure in the religion that worships Orholam, and is the highest church official. He is to balance the magic to prevent bane from forming. This is done by expelling certain amounts of counteractive luxin whenever an opposite luxin because too numerous. For example, if the amount of Blue luxin were to become too great, the Prism would draft large quantities of Red luxin to balance the disorder.
The religious doctrine states that there is only one Prism born per generation. However this is not true as both Gavin and Dazen were Prisms, a reality which sparked the Prism's war. The Blinder's knife can take the Prism's power away and it is alluded that it is used to make Prisms as well.