1950s style prom dress for Grease play This sweet yellow party dress was first seen in the 1978 , where actress Didi Conn wore it as Frenchie. After that, the dress very likely went into rental stock, where it Lee Pace Fan! costumeloverz71: Sandy Olsson (Olivia Newton John) Grease Summer Nights Sandy Party Time, Inc. This sweet yellow party dress was first seen in the 1978 , where actress Didi Conn wore it as Frenchie. After that, the dress very likely went into rental stock, where it