From Guild of Archivists

The Prism is the final stage of the puzzle whose solution grants the solver access to the Voltaic Linking Book Chamber within one of the tusks arrayed around the Age of J'nanin. This device takes the white beam of light that is sent into the rear of the prism and creates a five-color spectrum of red, yellow, blue, green, and purple, which is projected against a ring of buttons. Each button corresponds with one color, and when pressed in the proper order, the door will open.