See Olivia Newton John's Best Outfits as Sandy in "Grease" PS Fashion This sweet yellow party dress was first seen in the 1978 Grease, where it was worn by actress Didi Conn as Frenchy. After that, @recycledmoviecostumes on Tumblr 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 Grease: The Best Fashion Moments And Where To Shop Them periodedits : Olivia Newton John as Sandy Olsson GREASE (1978)