It was an “out-and-out disgrace” to allow Glasgow Warriors to wear a similar kit to Cardiff in their Champions Cup game, says Blues fly-half Gareth Anscombe.
Glasgow wore a marginally lighter blue strip as they won 29-12 at Arms Park on Sunday.
“I have never come across that in my eight years of playing rugby,” said Wales international Anscombe, 27.
“Who is making those decisions? It’s a joke.”
Cardiff coach John Mulvihill said: “We complained before the game about the jerseys. The jerseys were exactly the same colour.
“It would have been an absolute nightmare for the referee, an absolute nightmare for the assistant referees, and running into that sun in that first half the boys couldn’t differentiate who was their team-mate and who wasn’t. It was ridiculous.”
Under tournament rules, teams must submit two kit designs to governing body European Professional Cup Rugby before the start of the competition.
Two weeks before each match, officials tell the sides which strip they will be wearing.
“The kit data gets sent in and they looked at the colours and said there was no clash,” said Glasgow coach Dave Rennie after Sunday’s game.
“I’m not sure about that, and we would have been more than happy to bring our black kit along.”
A longstanding rugby tradition is that the home side change into their second kit if there is a clash of colours.
Anscombe said: “We told the referee and the touch judges early on. They told us it was down to the home team to change jerseys, but I don’t think that’s fair.”