I do my enhancements a little differently than how it was shown in the meeting. Take the image into PhotoShop, and duplicate the image. Turn the duplicated image into a black and white that you like and then, on the black and white layer, use the erase tool to only get what you want in color and the behind layer will show through :).
Go through the same steps as above, then go to the bottom layer and then Ctrl+U into Hue and Saturations and choose your coloring. You may have to play with the black and white layer to make it realistic.
p.s. this can also be done with teeth for whitening by making the bottom layer the black and white.