Maerlyn's Rainbow are artifacts that feature in The Dark Tower.
Maerlyn's Rainbow, also referred to as Bends o' the Bow and Wizard's Rainbow, were a group of magical objects that were made up of 13 crystal ball-shaped talismans. The sorcerer Maerlyn created the objects from "The magic of the Prim". He created them to bring chaos into the world, and he also created demons for every sphere. Randall Flagg, the bastard son of Maerlyn, had an affair with the demon of the Pink Bend of the Rainbow.
It is also stated in the same issue that six of these Bends are in the possession of the Crimson King. The only one mentioned by name in the issue is Black 13. The other five appear to be Blue, Lime, Yellow, Orange, and Purple. The Crimson King uses Black 13 to communicate with Walter O'Dim. These events occur around the same time that the Pink Bend is given to the witch Rhea of the Cöos.
The thirteen bends were: Crimson, Orange, Yellow, Pink, Dark Blue, Dark Green, Indigo, Lime, Azure, Violet, Brown, Pearl Grey, and Black.
- Pink Bend : also known as Maerlyn's Grapefruit which was in the possession of John Farson but was left with Rhea in Mejis when Roland and friends were sent there. Roland managed to take it home with him to his father, but it was stolen after the death of Gabrielle Deschain. Roland and his new ka-tet come across it in the Green Palace after a confrontation with the Man in Black. The crystal acted like a conventional crystal ball within the scope of the written stories, although more diverse uses are implied. When looked upon, it can show a single person visions of current and future events elsewhere, presumably only in the same world. Like the monkey's paw, the visions can be back-handed, lying through reflection or other tricks to manipulate the viewer towards evil actions. By showing a vision cast in a mirror, the Pink Bend was able to confuse Roland into killing his mother. Additionally, the glass can entrance the viewer and cause a severe addiction to being viewed.
- Black Bend : referred to as Black Thirteen that was given to Father Callahan by the Man in Black while Roland was chasing him. Callahan was transported to Calla Bryn Sturgis by it, and subsequently hid it away after settling down in the Calla. When Roland and his ka-tet arrive, he offered it to Roland as incentive for their aid. Eddie and Callahan subsequently use Black Thirteen to travel to New York City and Maine in 1977, in order to protect both Calvin Tower and the rose (this world's representation of the Dark Tower) growing on the vacant lot he owns. Mia steals it after the showdown with the Wolves and uses it to escape to the New York of 1999, where she plans to give birth to Mordred Deschain. Jake Chambers and Callahan follow and retrieve Black Thirteen, then store it in a locker beneath the World Trade Center. It is not known precisely what happened to it afterwards.
- Maerlyn's Rainbow was created by author Stephen King and featured in the setting of The Dark Tower.
- The Dark Tower: