If Moto says the real part has a red band and yours doesn't...end of story, it is counterfeit. Moto and many other OEMs color code their antennas because "they all look alike" and the color code makes ongoing maintenance simpler, since all antennas wear out and putting the wrong one on can blow a radio.
A counterfeit CAN be perfectly good, the art of designing an h/t antenna is about as complicated as a grade schooler "macaroni poster". Problem is that counterfeit usually means they will be cheaping out any way they can, so the connections internally may not hold up. The "rubber" may be a cheaper compound that will become brittle and break apart sooner...you just don't know.
But since you already have it, and you say it performs well (presumably tested for SWR?) then I'd say to just keep using it, unless you have recourse against the seller.
Counterfeit "everything" is big business today. The only way to know you are getting the real deal, is to know your seller, which often means paying full pop directly from the manufacturer. (Ouch.)