Here are eight movie stills from very popular blockbusters, so that you can get an idea of how color grading is used to help tell a story.

The most popular effect among action movies is the Teal-Orange look:

color-grading-samples-01

color-grading-samples-02

color-grading-samples-03

The Teal-Orange color combination can also found in scenes where there are no actors.

color-grading-samples-04

The Transformers movie is one of the films that I believe over-does the Teal-Orange effect.

color-grading-samples-05

But that is not the only look. Movies like The Matrix use green instead of blue, because it helps push its story forward.

color-grading-samples-06

The movie Amelie uses a different complimentary color combination, the Red-Green combination.

color-grading-samples-07

Post-apocalyptic movies like Terminator Salvation use a desaturated gloomy look.

color-grading-samples-08

There is no right or wrong way to color grade an image (or movie). It is all up to you, the artist, and the story you are trying to convey.