This is why we're editing the movies in the first place, you nitwit. We can MAKE him mysterious and ambiguous. It's trivial to remove his scene with Sidious, as many edits do. That he's the enemy of the Republic and therefore the Jedi isn't in dispute; whether he's actually a bad guy can be made to be much less certain than it is in the official cut.

And if you care to notice, I'm basing my argument for changing his sabre colour based SOLELY on the fact that most people will make the association red = evil, which you yourself admitted. Any more symbolism risks being wanky, but so does a lot of what we do here.