Photoshop is an amazing tool to use to edit your photos. If you would like to see what you or someone else would look like with a different hair color then Photoshop is the place to do it. Try out something realistic or add a funky color to your favorite celebrity's style.
Adobe Photoshop allows you to take colors from an image and alter them in maske mode. When working on an image and you need to change the hair color maske mode and the magic lasso tool will help just fine. This video will demonstrate how to change hair color in Adobe Photoshop CS4. It is not as hard as it looks.
You can also change the color of anything else in an image with Adobe Photoshop. The combinations are endless. Changing saturation properties, color masque levels, gradiance, and opacity you can get whatever result you desire, just include imagination.