For a movie like "Captain America: The First Avenger", what is the term for the phrase after the colon, i.e. "The First Avenger"? Is that called a "subtitle" or something else?
According to both Wikipedia and Websters, "subtitle" is used for both the phrase after the colon, and the text which appears at the bottom of a movie that is in a foreign language. So, your assumption is correct.
Thanks to Sonny Burnett for pointing that out.
It is called as Caption. Which represents the story of movie or differentiates the movie from same series of movies