I've seen plenty of boom-ops with gaffer's tape or duct tape on their fur covers. It was always to hold them in place so that the fur doesn't shift and make noise during quick movements. ...okay, a couple of times it was just there to hold old crappy fur together. Lol!
As long as it's back a couple inches from the front of the mic it's not going to interfere with the sound.
I think it is simply a Media armband that the Mic Op put on his blimp. I found a piece of video where a Camera OP has one hanging from a carabiner on his belt, the Mic Op has one around his blimp. And the band has some writing on it, possibly the name of the tournament. ( "British Open 2017" or something like that. )
Maybe the crew member didn't like wearing it around his arm so he cutely put it around his mic instead. The blimp is roughly the same circumference as an adult male's bicep. I've had Sound Ops place a media credential sticker on the front of their mixer instead of on their person. Like I said, there is a "cuteness" or whimsey about putting the credential on your gear instead of on your person. "Ha ha, look at that, he put it on his mic."
I find that more likely than it being any sort of color coding for the production. The person mixing in the truck is going to go by the golfer on screen and pot up the channel for the shotgun mic assigned to that pairing of golfers. The shotgun mic isn't going to be in the shot most times, so a color code wouldn't be of much use to the person mixing the sound. I think it was just a Sound guy being cheeky.