Adjustment Layer: Hue/Saturation
Using white color and a soft brush, paint over the skin areas so that only
they get treated. For the adjustment, switch from Standard to “Reds” (found
in the Hue drop-down menu of the Adjustment layer), and use the Hue,
Saturation and Lightness sliders to adjust the skin color. Switch to “Yellows”
and optimize the skin tone. Getting the colors exactly right depends very
much on the image material. Rely on your common sense.