Display variant in product list

The system is not made to be able to display the variants directly in the listings. So first option would require complex and time consuming coding to be able to do that.
Now changing the image of the main products on the listing when the filter selection changes, that's possible with some javascript coding in the listing view. That would be way more simple. An average developer with no particular knowledge of HikaShop should be able to do that.

Hi,

Well, what I would recommend is to name your images in a specific way.
For example, if the two colors you have a blue and black, I would recommend to have your images end with _black or _blue with the rest being the same.
That way, on the listing, when you change the filtering, you can use a bit of javascript to change the src attribute of the img tags in the listing area to replace "_black" with "_blue" and vice-versa. That way, you don't have complex loading of data from the server etc.