Checking Skin Tones
It is well worth checking on skin tones as this is a Key colour that does need to be realistic. The same basic method will be used here as was done with correcting neutral greys and sky blues in the previous sections.
If you don't know about the 'Key Colours' then read the section on Key Colour Patterns.
Reading the Image
A yellow colour cast is fairly obvious here. There are skin tones that can be used to check for the colour balance, but you need to be careful on where the readings are taken from. Avoid the top of the heads as there a lot of reflection from the sky, which would have been worse had the sky been blue.
Clicking on the forehead of the woman standing on the right with the Eydropper from the Toolbar shows that the sky Key colour pattern is a little stretched. The three sliders may be in a straight line, but the line is a little flatter than 45°. This means that the Red is a little too high, and the Blue is a little too low. This results in a yellow colour cast as both the Red and Green are too high relative to the Blue (Red + Green = Yellow).
Balancing the Red Tones
Leave the Colour palette open (it will be needed while the colour correction is being done) and open the Curves panel.
REPEAT WARNING: The sliders on the Colour palette need to be "active", meaning that they must move while the colour correction is being done as they will tell us what to do and by how much. After the Curves panel has been opened you MUST click again on the skin tone area being measured. If you don't do this the Colour sliders will remain static.
From the Channel drop-down list, at the top of the Curves panel, select the Red channel. Click on the middle of the curve and pull it down a little, watching the sliders in the Colour palette as you do so. Stop when the Red slider has comes to roughly 45° above the Blue.
Now select the Blue channel, and this time raise the curve until the Red, Green and Blue sliders are roughly in a straight line.
Sometimes correcting the separate colour channels can result in the image becoming lighter or darker. In this example the Blue channel correction was large enough to lighten the image. Use the combined RGB channel at the top of the Channel drop-down list and pull down the middle of the curve a little until the image looks better. This will not upset the skin tones colour pattern; it will just move the pattern a little to the left on the Colour palette.
The finished image now has the yellow cast removed. If you prefer to keep the image slightly warm then reduce the amout of the corrections in the Curves, but do be careful. Note that it is not a sunny day in the photograph, and if the colour cast is too yellow then you get an "artificial sunshine" look to the image which won't feel quite right.
Finally, looking at the Colour palette again and clicking on the woman's face with the Eyedropper Tool you will see that the colour pattern is now as it should be.