1. open your image. (CTRL+O)

2. using your magic wand tool, select the area you want to change colors. In this tutorial we're going to do her eyes.
Magic Wand Tool
Select Area

3. unselect (by pressing CTRL when you go to select) anything that isnt what you want colored using the "free hand" selection option.
Finalize Selection

4. duplicate the layer by selecting "duplicate layer" on your layers palette.

5. colorize your selection (Shift+L or Adjust>Hue and Saturation>Colorize).
Steps 4 & 5; Duplicate Layer and Colorize

6. with your selection tool still at hand, right click on the image to get rid of the dotted lines.

7. using the eraser, erase anything that makes the picture look better.

8. Go to layers>merge>merge all and you're done ^_^
Final Print