Note that color sanding generally refers to sanding single-stage, or at least it did back in the day when we'd wetsand paints like lacquers. You know, sanding color as opposed to sanding clear.
I've never found it necessary to sand paints (other than spot repairs), but then I'm never dealing with anything in really awful condition either. If you're talking about sanding out OP, then I'd sure think about it...and I'd be mighty careful. I've had some nasty OP (even on the A8/S8) but I've never felt the need to sand it down. IMO most people have their hands full just getting rid of regular marring.