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 Sold at Auction: Olivia Newton John, Olivia Newton John "Sweet Sandy" Outfit Worn to a "Meet N' Grease" Event Sandy Grease Yellow Dress Summer Nights Girls Party Costume 10 12 Years (Officially Licensed) Unique Vintage Dresses Unique Vintage Grease Rizzo Dress Poshmark