Products Variation System & Image Change On Variation

Hello, First of all thanks for such a nice theme with really detailed documentation. This is the best documentation of any theme i've come across so far.

Well about the concern, On the products page in demo, there are dual variations. 1st one is color variation & second one is size variation. But In our theme, i couldn't find the way to get this through for our products?

I also want to update fashion category products in dual variation as: color variation & size variation.

Also, when we click on any particular color, and size: it should display the image of that product in that variation in the main image but its also not happening in this theme.

Please advice how we can achieve the same?

as in the attached screenshot, i've clicked on purple gem with gold option but i didn't get the image of gold ring with purple stone in it now after selecting the options, it still showing the silver image with white diamond look awkward. isn't it...

Please suggest.