Quite a novel idea. Read the description on the page and that all sounds like it would be a great game, it's a sham that you couldn't implement a lot of it for the jam, but I'd love to see those ideas come to fruition.
One thing I'll add is that having to backtrack through an area you've been through already to get a specific color is not great, I thought it'd be cool if you could stand on a tile that you've already painted and crouch on it to get that tiles color, so as long as you're spreading the colors a lot, you'll have plenty of places to get them from if you need them again.
Anyway, some really cool and ambitious ideas here.