Threaten not to play and ensure the blame is strongly apportioned to the offending team. A compliant kit soon appears. Alternative is to play the game, tell the players it's not your fault when they pass to you and report it after the match.
I had this earlier in the season.
Away Team turned up in a 80% black kit with a stripe of pink. (And yes, it was as bad as it sounds). Home team in all blue.
I queried it and the manager said theatre had cleared it. As my kit bag was to hand with the league handbook in it I did - and sure enough they were listed as the correct colours.
They suggested I wear a bib at the start and I said no way.
Towards the end of the first half a bit of morning insured about a mix up with somebody mistaking me for a team mate.
At half time a couple of players suggested the bib again, still no way.
Early second half after a pass to my feet centre back shouts across the pitch at me (I f'in told you to put a bib on).
As I gave him his caution I loudly reminded him they knew I would be turning up in black months before they even thought about buying that kit, so perhaps they should be looking at themselves first.
Didn't have any other problems and reported it to the league. Although typically for this league they decided to do naff all.
My take is this: Follow the rules, make it difficult and they will be forced to address the problem completely. Wear the bib and become last weeks' ref. ('But last weeks' ref just put a bib on')
