It looks like you have the colors list in its own form. Drag the list inside the add to cart form or move the form tag so it encapsulatest the whole cell. They can't be in two separate forms.
Your friends over here at WebAssist! These Dreamweaver extensions will assist you in building unlimited, custom websites.
These out-of-the-box solutions provide you proven, tested applications that can be up and running now. Build a store, a gallery, or a web-based email solution.