Turn your whole room into a film noir without film.
how about everything is in Greyscale but... when you get close to something it gets its colour back !
like when a room is set to spooky and everything is black until you get close
extra points if instead of Greyscale its a colour you pick like green for a forest or blue for underwater or gray for noir
There would need to be a way to stop people treating it like free film though because I know that people will be like that
I would support this as part of a more general set of color filters.
Add more while you're at it, some default environments in the room settings aren't enough.