1. Open up a picture that you would like to add/change color too
2. Okay, there's two ways of doing this, you can either go to Filter -> Extract or use the polygonal lasso tool.
3. I'm using the 'Extract' method
Filter -> Extract and you should have a window pop up that looks something like this.
4. Now select the Edge highlighter tool with these settings.
5. This is the part that everyone hates. With the highlighter tool select the part of the image you would like to change the color of.
Zoom in the part you would like to change by clicking on the magnifying glass. Press OK when you're done
Select the paint bucket and select the inner part of the image that you have selected
6. This is what you should have when you have clicked OK
CTRL + A ( To select the whole image ) and then CTRL + C ( To copy the selected image )
Close the image and re open it
CTRL + V ( To paste the image ) and line up the image with your image
7. Now its the fun time, CTRL + U and change the color around! If you cannot find any good colors that matches your image, go to Image -> Adjustment -> Color Balance
