I saw on YouTube this nice colour correction, and now I want to ask you how to do this? Is there anywhere on YouTube (or I don't know) a tutorial for this?
--> [The colours from 16sec till the end] http://www.youtube.com/watch?v=iz2DRX4oxgI&feature=channel
Create a comp-sized solid layer above your footage layer. Apply the 4 Colour Gradient effect to the solid.
Switch the blending mode of the solid layer to Overlay.
Experiment with different colours and different blending modes until you get the desired result.