Backround "overlays?"

I got the “dynamic wallpapers” set up with the “blurry emulation station” preset I guess?

What im trying to figure out is if there is a folder where these files reside? Im not getting any backround for MAME or FBA… Also no backround for generic History and favorites etc…

What I think would be cool (and part of the nostalgia) is the blurred out backround with one side with a picture of the console, a cartridge, and the controller…

So like you put both thumbnails on the right and on the left it shows the console itself with etc.

what would also be cool would be to make the place on the screen where it has the actual text for the console (top left), be a solid color so its easier to read and maybe the rest of the top of the screen has the consoles trademark lettering splattered across the top.

Does this sound like a good idea?. I know it will add a lot of visual pizzaz without much effort.