This is an interesting legend, but the photo was taken in 1979 in London, where there were no “white only” clubs. According to Mark Hamill who played Luke Skywalker, Jones never put on the Darth Vader costume.

David Prowse who played Vader in the original trilogy also denies his presence in this photo saying that the costume looks “too cheap” and the person who is wearing it is “not big enough to be Darth Vader.” It was probably just a fan who was accidentally confused for an actor.