In Paper Mario: Color Splash, the game takes place on Prism Island.
Mario and Princess Peach travel there after discovering a color-drained Toad folded into a letter. They arrive at Port Prisma, where the island’s colors have mysteriously vanished and the Prisma Fountain has stopped working. Its guardian, Huey, explains that six Big Paint Stars normally supply the island with endless paint and color.
Mario’s adventure involves crossing Prism Island’s themed regions, recovering the missing Big Paint Stars, helping Toads, and battling enemies using painted cards. The island’s identity is easy to confuse with Port Prisma, the colorful town where Mario first arrives, but Port Prisma is only one location on Prism Island.
The game’s paint-focused setting also explains its visual style: environments resemble paper, cardboard, fabric, and other craft materials. Color Splash was developed by Intelligent Systems and released for Wii U in 2016. Its story ultimately reveals that Bowser’s attempt to recolor his shell created dangerous black paint, leading to his transformation into Black Bowser.