1. Have you ever wondered how you can change the color of someone's hair in a picture using photoshop? This is the ultimate solution! Open a picture in photoshop (I used a picture from this site to start with).
2. Make the skin look nicer and give her a tanned color with this tutorial tutorial so she looks like this!
3. Use your polygonal lasso tool to select the hair of the woman on the picture you chose and when you've selected it like this, copy it (edit - copy) and create a layer (layer - new layer) and paste it on the new layer (edit - paste).
4. We are now ready to change the hair color on the new layer! This is done by changing the color (image - adjustements - hue/saturation)! Be sure the check the colorize box!
5. And this is how it looks when you compare the pictures (you should also use the blur tool to blur the edges of the hair to make it look nicer)!
More Tutorials: 
Great tutorial!