For many people, New York City past is a study in black and white. It is the world of Erwitt and Klein or Winogrand, of Weegee and Arbus, of film noir. As history, black and white seems to encompass the city: gritty, dirty, and real. Black and white is so ingrained in peoples’ minds, that this is the true New York. This is the exciting place they have dreamed of visiting or living in. But for Saul Leiter, New York…