Matching Skin Tones

A sunburn or a blush can disrupt a portrait, especially if there is a contrasting pale person nearby. Photoshop has a tool to correct that: “Match Color” offers control over skin tones. Open your image and use the Quick Selection tool to roughly select the red skin areas.
You can hold down the Alt/Option key and subtract areas from the selection. Click on Select → Modify → Feather and enter a value of about 15 pixels. Use the Control/Command + J shortcut to copy the selection to a new layer.

                                                          Adjustments: Match Color
 
Using the same technique, copy the non-reddened skin to a new layer. In the next step, you’ll have to differentiate between the source layer and the layer to edit, so rename these two layers meaningfully; all it takes is a double-click on the layer name. You could use the naming scheme shown here and call them “Beautiful skin” and “Reddened skin.”
Activate the layer with the red skin, and select Image → Adjustments → Match Color from the menu. For “Source,” select the current document, and for “Layer,” select the one with the beautiful skin. Control the effect using the “Luminance” and “Color Intensity” sliders in the Image Options area. Once you confirm, you can control the effect’s strength with the Opacity slider.

 Paler skin after Match Color