It was a black tie affair with a casual twist at Foot Locker’s “On Our Feet” gala on Tuesday. The occasion, held in New York’s Gotham Hall, asked guests to wear formal attire — with sneakers. Attendees included a mix of executives, athletes and celebrities, including “Gossip Girl” star Chace Crawford, the New York Jets’ Darelle Revis, ESPN’s Jay Williams and supermodel Quiana Grant. A silent auction of memorabilia helped raise money to support the United Negro College Fund. To date, more than 370 college scholarships have already been provided through the annual event.