"Multiplication color by number (lots of varieties) This is an online activity that would be great for early finishers, or for kids who need extra math practice!" :: Some of my young grands are just plain smart, and like fun stuff like this!
Math: Area math game: Roll the dice and draw the area array on your own grid - first to fill it wins. Or 2 players choose a different coloured pen each, use one grid and the player who cannot complete the last array is the loser.
Sub plans. Could use at any grade level, with a particular color group, such as warm/cool colors. Could also be a good sub plan. "The longest line - draw continuous line to fill entire paper, add shapes and color inside them"