I didn't say you'd have the same colors/polys on every screen.
I meant like, just an example, if you can click somewhere to go in a cardinal direction (considering the north/east/south/west properties on rooms), you'd have the dark blue, green, cyan, and red colors mean "go in that direction". Depending on the visual size and shape of the room, a given direction might need to be closer to the center or whathaveyou, or not be an option at all. Or perhaps there's a default response to clicking on the sky, if and where it's visible, that's the same throughout the game?
It's like having a general "in water" color in a regular game with a visible Ego walking around -- not all rooms have water in them, and those that do don't have the water in the same places.