Black headbands that look grey!

[Clark Kent]

GJV game tonight. First time in awhile that I've had a girl's game. The home team is in white and four of their players have black headbands, then there are two with what looks to me like gray headbands. I approach one of them with the gray and ask her what color her headband is (my sisters taught me early on that they knew their colors better than I ). She replies black. As I come to find out it was black pre-wrap that when stretched looked very gray. I've seen the "gray" pre-wrap before but this looked much more gray. I do a pretty good job of sticking to the rules with the headbands, but tonight I was a bit weak I guess and let them play. Now I'm looking for opinions on what I should've done?