The much talked-about gown he's made for Lauren Davis' Cartagena, Colombia, wedding to Andres Santo Domingo is still under wraps, but Olivier Theyskens was happy to be in New York today, showing off his pre-fall collection. Motifs that are quickly becoming Nina Ricci signaturesshort dresses that twist around the body; narrow but never uptight suits; slouchily asymmetric sweaters; and a muted, dusty paletteabounded. This time, they called to mind not club kids coming home from an all-nighter, as the designer's Spring collection did, but the more sophisticated atmosphere of the London and Paris salons of the 1930's. Imagine Nancy Cunard or Vita Sackville-West lounging in a dove gray dress with a rolled silk neckline that trailed down the bodice like a wisp of smoke, and you get the picture. Equally lovely was a watercolor floral silk evening gownit'd be just the thing for a society wedding, but we're guessing Davis doesn't plan on sharing Theyskens this weekend.