It is possible to achieve what you want to do,but you need to modify the code.Here's a starting point for you.You need to take a look at the below files :
1. default_html5/template/pages/product/product.tpl -> this is the default product page,find the code that renders the
2. default_html5/template/pages/product/product_listing.tpl -> this is the product listing page to be rendered in category page.
With the controller that handles them so you know which part of the code ouput the options.
Hope it helps.