I can see this being quite a show stopper for some people as many things require a few variables. Clothing being one of the main things
2 drop downs per product would be good yes, then they can pick one of each , one for the colour and one for the size.
I reckon now the best way if for me to make loads of options which cover all the items, it's just some have almost 14 colours to choose from, so will need to make 42 options to cover them all (eek!)