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 :).
There's also another fun trick that you can do, I dont have the best example, because I haven't take the time to do these right in a long time but below is an example of a very quickly done color change. This allows you to change shirt colors, eye colors... anything you can imagine. Its done the exact same as above, but takes more time and precision then the first one.
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.