(Justin Tallis/AFP/Getty Images)

“Any undergarments,” however, “that either are or can be visible during play (including due to perspiration) must also be completely white except for a single trim of color no wider than one centimeter,” Wimbledon’s rules state.

Canadian tennis star Eugenie Bouchard did not have a good day on Tuesday. Amid losing, 7-6, 6-4, to her unseeded Chinese opponent Duan Ying-ying, last year’s runner-up was nearly flagged by umpire Louise Engzell for seemingly violating Wimbledon’s strict dress code, The Daily Mail reports.

“I was not aware of that at all,” Bouchard said on Tuesday when asked about Engzell checking on a possible wardrobe violation. “And no one told me anything about my bra.”

Under Wimbledon’s rules, players must dress “almost entirely white.” Exceptions are generally given for small sports logos, like the black Nike swoosh on Bouchard’s tennis tunic.

Roger Federer was the last high-profile tennis player to get busted for breaking the rules at the All England club. In 2013, he was dinged for wearing Nike shoes with bright orange soles.

The 21-year-old’s choice didn’t seem to cause any other Wimbledon officials to get their all-white panties in a bunch.

Bouchard, who entered the tournament seeded 12th, could be seen wearing a black bra, a detail spectators could see only because a sliver of the the strap peeked outside her otherwise all-white uniform at times when she moved.