Premise: Happy Go Lovely is a 1951 British musical comedy film with Technicolor, directed by H. Bruce Humberstone and starring Vera Ellen, David Niven, and Cesar Romero. The film was made and first released in the UK, and distributed in the US by RKO Radio Pictures in 1952.
Hypothesis: Vera Ellen, David Niven, and Cesar Romero starred in Happy Go Lovely