I was wondering if different areas in the submission could use a different color pallet of four colors?

So that way no more than 4 colors would be present on screen at the same time, but the colors being used could change depending on where you went.

I was planning on doing this. I feel like it creatively bends the rules :)

I was wondering this too, and I read the rules again, it says "Use only 4 colors in your game", I guess it means the entire whole game, not just one screen at the same time.

I'm sticking to just 4 colours in my game, but the game is displayed inside a 'Super Gameboy' style window the outside of which will have any colour (but isn't part of the game, it's just a border)

The game itself will stick to 4 colours total, but I'll give the player a number of 4-colour palettes he can flip between kinda like the super gameboy again.