Manchester United legend Gary Neville says Sir Alex Ferguson's hatred of their infamous grey kit was not a whim.
The strip went down in Premier League folklore when United travelled to the Dell to take on Southampton towards the end of the season.
United found themselves 3-0 down at the break when Ferguson demanded his players got changed. They emerged for the second half wearing a completely new blue and white kit.
Ferguson felt it was difficult for his players to see each other and Neville has confirmed there was a theory to his belief.
"He hated that kit but there is a science behind it. Sir Alex had employed a professor on sight, a vision specialist," Neville said speaking on the Quickly Kevin, Will He Score? podcast.
"She brought in a lot of eye and alertness exercises and said to Sir Alex to imagine a crowd behind you, there are colours you can see more than others.
"It is the reason people wear bright yellow on a motorway. She believed when you saw these grey kits that the players won't pick each other up at a distance.
"It had been going on for months and he had rejected this kit a couple of months before. He wasn't having it."