To be fair, the referee is officiating a professional sport where you really need to be able to clearly distinguish between the legs of two people lunging quickly for the same ball with their feet.
Probably sounds silly, but when that's what 95% of the sport revolves around, you can understand them being picky on a detail like this.
Oh yeah that makes a lot of sense
The Football Association's (FA) rules state teams must wear colours that distinguish them from each other.
Why can't they play with matching socks?
To be fair, the referee is officiating a professional sport where you really need to be able to clearly distinguish between the legs of two people lunging quickly for the same ball with their feet.
Probably sounds silly, but when that's what 95% of the sport revolves around, you can understand them being picky on a detail like this.
Oh yeah that makes a lot of sense
(from: https://www.bbc.com/sport/football/68579553)
It's much easier to tell who kicked the ball out when teams have different color socks.