I used an extension a while ago that changed CSS colour values (#ababab) into little coloured dots, that became a colour picker when clicking on them (while still letting you input RGB or Hex, ofc), and it was pretty awesome!

So, I could unironically see this being really nice. Although... I think this would need a pretty narrow context, something like if x == true would look pretty confusing as a toggle, I imagine. But assigning x = true? Bring it on.