My carbon bikes are tube-only, so I mask at the lugs, sand the trouble spots to remove the scales, scuff up the rest of the tube, wipe down with mineral spirits, let dry, then shoot the tube with the clear. I always rub it down a bit with compound to make it smoother, then wax.
I've done the same with CF seatposts that have conspicuous lettering I prefer not to see. My CF Trek has zero defects (Thanks, Force) so there were no problems there, but the Ironman took some work on the DT between the bottle cage "inserts."
On a one-piece Kestrel Talon I had, I blocked off sections that had been scuffed in storage, did the same. When it dried, I feathered the edges with some rubbing compound and a foam wax applicator, then wiped carefully with some mineral spirits and let it dry, then waxed. You have to look for the "line" to find it.
The other alternative is simply mask the area, and shoot it, then you'll have a more defined line between the repair and the masked-off area, but sometimes that's less conspicuous.
Use both sides of the towel.
1985 Raleigh Racing USA - Competition (honoring cehowardGS)
1988 Centurion Dave Scott Ironman Master
1989 Centurion Dave Scott Ironman Expert
1989 Centurion Carbon R