if you load up a game, you will see the player screen...
in that screen you can change the ais etc. (i.e. turn all ais off) though it doesn't seem to effect the game (i.e. all ais are still there)
the only thing it did seem to affect was the statistics when finishing the game though (i ended up with only my statistics displayed instead of all statistics)

so i guess that settings should just be locked there (though being able to change colors on loading a game might be interestings if you want to continue the save of someone else)