I would describe it as follows, maybe a little easier to visualize. Draw six dots, draw either a red or a blue line from every dot to every other dot. You must

I would describe it as follows, maybe a little easier to visualize. Draw six dots, draw either a red or a blue line from every dot to every other dot. You must draw either a completely red triangle or a completely blue triangle. Personally I don't think it sounds intuitive when stated like that!