LOUISE: Tristan usually likes his girls bad.
MADELINE: Looks like we’re going to have to do the Pink Ladies makeover on you [Paris].
LOUISE: We’ll turn you from a sweet Sandy to a slutty Sandy. Dancing at the school fair with high heels, black spandex, and permed hair.
Madeline and Louise are referring to the 1978 romantic comedy musical film Grease, directed by Randal Kleiser and based on the 1971 stage musical of the same name by Jim Jacobs and Warren Casey. Set in the late 1950s, it is about the relationship between a “greaser” named Danny Zuko (John Travolta) and a “good girl” named Sandy Olsson (Olivia Newton-John).
In the film, Danny and Sandy are genuinely in love, but their relationship keeps hitting problems because Sandy isn’t well accepted by Danny’s friends. The Pink Ladies are a group of popular girls at the local high school who give Sandy a “bad girl makeover” to turn her into a greaser’s dream date for Danny, just as Louise describes.
Grease was a massive box office success, and the #1 film of 1978; at the time it was the highest-grossing musical. It gained good reviews for being fun and imaginative, and is considered one of the best musicals of all time, as well as one of the best high school movies.