Working with an image's existing colors

Program I use: Photoshop CS5

I am so out of touch with the latest icon making techniques but one thing I’d definitely like to learn is how to work WITH a screen capture’s original coloring instead of against it. I always want to change orange looking caps to look more natural by adding blues and such and they come out looking faded and gross. Here’s a perfect example of what I’m talking about:

This (made by geckoholic):
imagebam.com

From this:
imagebam.com