Attributes - impact on price using multiplier/percentage

[kizviat]

Hello there,

I'm new to prestashop and these forums so I just hope I've been looking everywhere I could to get answer to this so I didn't bother with dumb question. If I do, pardon me.

 

I need one specific attribute of a product to have "multiplicative" impact on the product price - e.g. I want a red ball to always cost 1.2x the red ball (which is default combination) (let's say even for all 'sizes' of the ball, always 120% of the default).

 

I cannot see any option to do that in presta - is it even possible please? If so, how can I achieve this?