We will investigate both. In any case, I agree that users should be able to override pre-determined styles at the individual survey level. In my suggested implementation there would be less UI work to do which might make it more viable to prioritize. We'll see what works and what feels good.
In any case, I will bring it up with the team and it will be reviewed at our first opportunity. We are working on some pretty big features right now so it might be a wee while before we can look at it.