Most colleges only offer Film Scoring as a grad course.
Is it possible to take a film course as an undergrad, and then the film scoring course as a grad? Or does the film scoring course require you to undergrad in something music-related?
Berklee offers an undergraduate degree in Film Scoring. https://www.berklee.edu/film-scoring/major
This is also useful: http://www.nickdolanmusic.com/blog/film-scoring-programs
You should major in something music related.
if you look at the Music Masters in Film Scoring at the Seattle Film Institute. it says:
Who Should Apply to the MM in Film Composition?
Composers/musicians with an undergraduate degree and advanced training in music.
Individuals seeking to launch a career in composing, orchestrating, and producing music for film, TV, video games, and other media (web and flash-based media, advertising, corporate materials, etc.)
Active Film/Media Composers with some experience seeking the thorough, formal training needed to take their careers and work to a higher level.