Prismatology is a philosophy founded by Hugh Bliss. Prismatologists pursue various mental exercises in order to attain a state of true bliss. Bright colors play an important role in prismatology, especially the colors of the rainbow. The tenets of prismatology are recorded in the book "Emetics: the handbook for multicolored happiness by Hugh Bliss".
The main headquarters of the prismatology movement is the Blister of Tranquility on the moon. In Bright Side of the Moon, Sam & Max pretend to be prismatologists in order to get inside the Blister.
The movement seems to have dissolved after the death of its founder, as it is not heard from or talked about after Season One other than when Mr Featherly briefly mentions regretting ever being part of it in What's new, Beelzebub?.
It is a thinly-veiled parody of Scientology (Emetics being a reference to Dianetics).