Color & image component properties

I’m working on a template design system that will be used by a companies social media team. I’m specifying pretty much every last bit of each template so it would allow them to just do the editorial side of things like exchanging text contents, colors and images. I really dig the ability to being able to leak certain properties and simplifying instances, so they will end up with quite a focused view of what is changable and what is not. This is important as it won’t encourage them of breaking the system casually. All I am wishing for in a while now is being able to set a color and image property. I think as it is now, this is handled inconsistently and unintuitively. It would be exactly like “selection colors” is handled in UI2, but set as a property value. Same goes to images, would be amazing to being able to allow them to interchange images quicker, not having to comb through the instances layers.