Note that if you don't set the product to maximum 1, a customer might want to order 3 different packs, select 3 colors and enter qty: 3, thus ordering 9 packs. If you do set max 1, a customer who wants 2 red packs and 1 blue pack will not be able to order that combination.

You may be best off with radiobuttons so a customer only adds one color (in whatever quantity they want) at a time. They can then go back and order some of another color. A bit longer, but allows clarity and flexibility in ordering. You don't want to confuse the customer! :)