Which tennis open can only wear white clothes?

At Wimbledon, players are required to wear white tennis clothes to show their respect for the British royal family. It's a traditional problem. But things have changed recently. It is reported that since June 26th, 2006, Ralph Lauren, an American fashion brand, appeared at Wimbledon Stadium in navy blue uniform, taking photos for 570 referees and caddies. This is the first time in the history of Wimbledon 129 that a foreign brand has been appointed to design clothes for its judges and staff. The most stubborn tradition has finally taken a small step forward.