Also, another great way to change the color of something like skin would be to do it like this.
1.Create a new layer (Layer | New | Layer) or Shift+Ctrl+N
2. Go to the paintbrush and select what color you want the skin to be. Also select how big of a brush you want to use. No reason to use a really small brush if it's for a big area.
3. Select the layer mode to either color or overlay (the layer mode drop down box is right under the layer tab on the right side)
4. Now just paint over the body, it'll change to that color.
I love this way because no change you make is permanent. You can go back and use the eraser if you painted too much or out of the lines. If you decide you want it to be a different color after you're done with it, you can just go to hue and change the hue of that layer. Or if you decide you don't want to use any color you can just hide the layer.