Meme alert! A cinematic rainbow for a gloomy winter day! (As always, I have seen and can recommend all of these).
Red River (1948)
A Clockwork Orange (1971)
Golddiggers of 1933 (1933)
The Night of the Hunter* (1955)
The Moon is Blue (1953)
The Purple Rose of Cairo (1985)
Grey Gardens (1975)
Black Narcissus (1947)
The White Ribbon (2009)
* Hunter is totally a shade of green, you guys. What? The Green Hornet and The Green Lantern don't come out til next year. JUST LET ME HAVE MY RAINBOW, DAMMIT.