We have common questions where our sellers would like to show different variations of the same product. For example, some would like to have one listing where the buyer can select a design on either the shirt's front or back.
So what you want to do is this:
Use the "Clone" feature to duplicate the product you want to do this with
Set the product set to use our "Grouping" feature
Using this method will group your products into one listing, and you can add different designs with different colors that way.