Few people likely walk out of a movie and comment on the palette chosen by the director off the colour wheel. Those conversations are typically reserved for art classes or nerdy film forums. But colour, whether it is immediately noticeable or not, is a storytelling device that is exhaustively planned by any competent filmmaker.
This conversation can be as simple as: The dress in Schindler's List was red and the rest was black and white. Or it can be more technical and nuanced, like in the case of O Brother, Where Art Thou?, where the cinematographer first used digital colour grading to remove the green and then coated the film in dust. These effects, as explained in Cinefix's latest video, are done by picking select colours to enhance. Wes Anderson very intentionally picks colours that make his movies look like a fuzzy, pastel hipster dreamland. And Alfred Hitchcock used opposite colours on the wheel in Vertigo to dress his characters in red for caution and green for envy.
Or you can be like Michael Bay and paint every movie the beautiful colour of fiery explosions.
