high contrast in the midtones but muted contrast at the extremes, along with desaturated neutral colors but saturated vivid colors.The "desaturated but vivid" look (a-la the movie 300) is easily accomplished by making a black & white layer, and then putting a color layer on top of it and using the "overlay" or "soft light" combination method. To make it look more like a classic film, rather than straight black & white, make it a sepia and then put the overlay on top. You can actually achieve a wide range of effects by how you handle the black & white (or sepia) step.
There are a million ways to tackle any problem though, and I'm just guessing here because the technique really depends on what your original looks like and how much help it needs getting to where you want it.
(If you want to upload an image somewhere, I could play with it and let you know what works.)
posted by Fifi Firefox at 2:23 PM on June 5, 2010 [1 favorite]