A Photoshop tutorial describing how to use the Color Range command to select a portion of your image based on color.
See the whole course on Lynda.com. http://www.lynda.com/Photoshop-tutorials/Practical-Photoshop-Selections/96664-2.html
If you aren't a member, sign up for a free 7 day trial and watch the whole thing. www.lynda.com/trial/rharrington