That's highly unlikely. Because then the TO or the other guy can't tell what dial you actually have. You're allowed to make a mark so you can tell your dial from the other persons. But painting the whole thing black is not by any means the same thing.If you have a TO who won't allow you to use a dial from the wrong faction, they won't let you use one painted black either. The TO has the final say and can tell you that you can't use those dials.All black dials with ship type printed on it should be legal.
But then again, if I use the front of an Y-Wing dial, with the back-part of an A-wing dial it still looks rebel but is utterly wrong.
So what's wrong with painting them all black?