Colorio starts with players using plastic tokens to cover the colored spaces on the 5x5 game board. On each turn, a player must remove three tokens from the board, then either remove all of them from play or place one or two of them back on the game board in spaces different from where they came. (Thus, at least one token is removed from the board each turn.) A player cannot remove the final token handled by the previous player.
If a player reveals the fifth space of a color, that player is eliminated from the game. In a two-player game, the remaining player wins. In a game with more players, the game continues with that color (and that player) being out of play; when the fifth space of another color is revealed, that player is also out of the game. Plays continues until one player remains in the game.