Using another image instead of black for dynamic lighting

Hi, So I had an idea for an effect that I was wondering whether it was possible or not. I want to use the dynamic lighting feature to have the field of vision going on but instead of it being pitch black in the areas that the players can't see, I wanted it to be like an outline sketch drawing of the area and then in the areas they can see it be colourful and filled with the details there. Is there a way of setting it so the default thing the player sees with dynamic lighting on isn't black but another image I can upload?

Here is a post explaining something like it. Basically, put the 'outline sketch drawing' in the map layer, then the actual map in the token layer. Once the PCs get close enough, parts of the token-map should become visible in their Line of Sight.