OK, rage comment, GO:
Red - nice. I think you could take the cap out.
Orange - I'm afraid this would be useless. How about granting a creature +0|+1?
Yellow - cool, good for monos/duos
Indigo - by may you mean "if they don't have 7 cards in hand / only 1 card in deck they draw 2 cards"? Also, I think you should find a way to have them stack, without making them OP, because stacking is fun.
Violet - nice
Also, I think the names are not too good, but I was just commenting on the ideas.