Monochrome

"Monochrome" is a word meaning "one color". It is used frequently in rules of pyramid games, because pyramids come in different colors, and the colors usually have significance to the game.

Pyramids used to be sold in monochrome Icehouse Stashes; now they are sold in 5-color Treehouse sets.

Monochrome Chess, a game invented by Andy Looney, is the inspiration for his later invention, Martian Chess.