If they took the field in all black tonight, they wouldn't be able to perform for ten minutes because the stadium would be going nuts.
That having been said, I like white. It fits them better and it fits the show better.
I think this whole dirty feet thing is a conspiracy anyway. They just want to come up from underneath so their first all out victory will be more dramatic. To do this, they're intentionally keeping their visual a bit messy. Tonight, not only will they clean up their feet, they'll be marching an entirely different visual book.