Paint mode extension

I"m sure Unity isn't the best thing for this... but I want to do it anyway :)

I'd like to create a painting interface (or extension) that allows the user to add zones to a map... for example, consider a plane, and then the user paints sections of that plane with arbitrary colors, where each color represents a different zone (or territory).

My goal is to then generate some objects and place them in appropriate zones... but that's not really part of my question. Should I just look to some of the current extensions to see what is possible in terms of paining on objects?

Cheers.

Yes... You need to learn how to do the interface, and looking at examples is a good way to do so =).