Thanks for your response.
I use grouped product because it has the same model # but different colors with different UPC's. I need to store and track the UPC because our store is also on Amazon where the UPC is like the unique identifier in their catalog.
It probably doesn't make sense to use color squares in this case. What I actually want is to have color squares to show up on the product grid, not product detail page, so people know there are more colors available for a particular product, before scrolling away, like: http://www.toryburch.com/clothing/sweaters/?icampid=cl_cm3txt. This is on my todo's.