Roger Federer can't walk into a store without being mobbed—or so it goes in Wimbledon Village. When he appeared at the Uniqlo store with his wife Mirka, a eager gaggle of fans came running.

Playing in only his second tournament with Uniqlo gear, Federer went from his all-white Wimbledon look to the bold, all-black look. The Darth Vadar term for Federer's all-black choices was first ...