The good thing about Adjustment layers is they don't affect the base
picture and can easily be deleted, leaving the picture unaltered or they
can be adjusted later to change the settings you've previously made. Here
I've gone back and made the background more vibrant and you'll see from
the layers palette that I have added a second adjustment layer.
The areas in white in the little boxes are the areas that are affected
when you make changes in the adjustment layer. So Hue/Saturation 1 affects
the background and Hue/Saturation 2 the model.
To make the new Adjustment layer I first went to Select>Load selection
and brought back the "hair" selection that I had saved earlier.
I then went to select>inverse (Ctrl+Shift+I). This inverts the selection
so when you add an Adjustment layer it's the model that will be affected.
I chose Hue/saturation for the Adjustment layer again and played around
with the sliders increasing saturation to bring out the skin tones and
red in the lips.