The film starts with the bright pink wagons of the Healey Theatrical Company being chased by debt collectors and sets the tone for the rest of the film.
Sophia Loren plays Angela Rossini a role based on the real life actress Adah Isaacs Menken (1835-1868) who acted in the west during the mid 19th century and the scene in the play where Mazeppa escapes on a horse was Menken's speciality. I believe the "Heller" in the title comes from the quote that "Menken was a hellion in pink tights".
There is a love triangle between Loren, Anthony Quinn (Healey) the impresario and Steve Forrest (Mabry) a gunman. The story has a certain endearing quality but one never feels really involved with the characters nor does the action ever really excite.
Despite good acting and production values the whole film is clunky and contrived.
The main problem seems to have been Sophia Loren's husband Carlo Ponti (who was joint producer) exerting undue influence during the cutting process to accord Loren maximum screen time, resulting in the director George Cukor disowning the final cut.