The most-watched Premier League game in British history between Liverpool and Manchester United was un-watchable for hundreds of thousands of viewers, who are colour blind.
Almost five million football fans tuned in, but an estimated 300,000 of them struggled to tell one team from the other.
Supporters who experience ‘colour vision deficiency’ were horrified to discover United had chosen to wear their away strip for the match at Anfield, which is ‘earth green’, while Liverpool wore their traditional red kit.
Green and red, particularly in darker shades, are indistinguishable for many colour-blind people, who gave up on the contest long before the end because they simply could not see who was who, resulting in hundreds of complaints.
‘I ended up switching it off,’ said Kieran Maguire, a football finance expert, who is colour blind. ‘It was too baffling. Where the colours are broad of the same degree of light or shade then, as a colour-blind person, you have a problem.
‘This was the biggest match of the season and generated record viewing figures and in the end, I spent my time swearing at the TV because I could not tell who was who.’
The potential incompatibility of red and green is well known in football. The FA has produced a video to highlight the difficulty colour blind people have distinguishing the two colours.
And the Premier League has developed a ‘colour-blind friendly flag’’ which identifies the best kit combinations for people who are colour blind and uses a ‘bespoke online software tool’ to test whether strips should be worn together.
Clubs submit their kit choices to the league ahead of matches for approval.
In this case, Sportsmail understands the Premier League indicated in the days before the game that there was a problem and United agreed to change the socks from green to white to address the issue.
The club believed this would solve the problem, but in the event, while it helped, it was not enough and viewers still struggled to tell the teams apart. United are now aware of the issue and have responded directly to complainants, including Maguire, explaining what happened.
Sportsmail understands they accept the change to the socks was not enough and would make further changes in the future.
Embarrassingly, United’s star midfielder, Bruno Fernandes, is a colour blindness ambassador for the Portuguese FA.
Liverpool visits Manchester United this weekend in the fourth round of the FA Cup with the Merseysiders expected to wear their teal away kit. It is understood this kit has been tested against United’s red stripe and the lighter tone means it will be compatible.
In Britain, one in 12 men and one in 200 women are colour blind, with three million people affected in total.
During the Liverpool-United game, hundreds of fans took to Twitter to voice their anger over the strip selection.
Disappointed fan, Mark Abbott tweeted: ‘@skysports have introduced snicko, ball tracking, player cam and all manner of innovations to, presumably, make watching sport better on their platforms.
‘But it’s beyond their whit to insist one club wears a light strip and the other a dark one? Ok. It’s near impossible to fix…
Chris Hope tweeted: ‘Virtually indistinguishable to me. Absolute joke.’
Hope and Abbott were not alone is making their disappointment known.
‘Sunday was the most kit clash complaints we have ever had,’ Kathryn Albany-Ward, CEO of Colour Blindness Awareness told ESPN. ‘We had hundreds.’
“It is a really common problem, and it is a big problem because of the number of people affected.’
This is not the only match to have suffered a kit clash in the Premier League this season.
The game between Southampton and Sheffield United also sparked anger when they lined up in red and green combinations.
In America, the NFL had to change their approach to kits after a match between the all-red Buffalo Bills and all-green New York Jets in 2014, which could not be told apart by 14 million colour blind people, who then protested vociferously.
“The NFL had to change their kit regulations to make sure that it didn’t happen again.
“I think they do need to rise to a large extent in the UK. People are aware of it, but they don’t retain the information long enough to do something about it.
“If a major broadcaster was to take this on, and present what it is like to be colour-blind and watch a game to the right people. I think that would be great.
“The Premier League does act, and they do notify the clubs, as they know when these clashes will happen. I know because I was in touch with them today.
“They told United of this issue and United suggested a solution, but what they decided was not sufficient.”
The Premier League says it works with clubs on selecting the best kit for each match.
‘The Premier League has a detailed process in place to ensure that the kits selected for both teams in all fixtures are identifiably different colours and to ascertain the best possible kit combination for each match,’ said a spokesman.