I'm trying to set up a specific product to have a permanently fixed background image (so the variation image overlays). 

https://thedooraccesscompany.co.uk/product/paxton-bundle/

I've set my variation images to have a transparent background. The idea is to have the variation overlay over the featured image. Is this possible?

Ive remembered I used a plugin Yith product options to do this previously

Sorry to have bothered you