Today’s Question: I have noticed that on some of my older photos of people their skins tones are decidedly red. What causes this and how can I resolve it?
Tim’s Quick Answer: A strong red color appearance for skin tones (or other colors, depending on the ethnicity of the person) are generally caused by over-saturation. Reducing the saturation for only the affected colors will generally improve the appearance of skin tones in a photo.
More Detail: Accurate color can be important for any photograph, but when it comes to skin tones color accuracy is especially important. In many cases you will find that saturation levels that are too high will lead to color problems for skin tones, such as a strong red appearance in photos of Caucasian subjects.
Some cameras (or films) may have a particular bias toward red, such as by interpreting reds at too high a saturation level. Increasing the saturation for the photo can also cause skin tones to have an inaccurate look.
The first step, of course, is to make sure the overall color for the photo looks good. That certainly involves shifting the color balance (such as with the Temperature and Tint sliders available with most raw processing software) to get the color as accurate as possible. With many photos you may also want to increase the overall saturation to create a more pleasing look. The boost in saturation, however, can make skin tones look too saturated.
In many cases this issue can be easily resolved with a targeted reduction in saturation. For example, if the skin tones look too red you can reduce the saturation for only the reds. In Lightroom or Camera Raw, for example, you can reduce the value for the Red slider under the Saturation heading in the HSL (Hue, Saturation, Luminance) set of adjustments. In Photoshop a similar result can be achieved by choosing Reds from the popup for a Hue/Saturation adjustment, reducing the value for the Saturation slider after selecting Reds.
Of course, if there are other areas of red in the photo that you don’t want to reduce the saturation for, the above approach won’t work. Instead you’ll need to apply a targeted adjustment, such as by using the Adjustment Brush in Lightroom or an adjustment layer with a layer mask in Photoshop. And, of course, these same concepts can be applied to any area of problematic color in a photo, even when it isn’t necessarily a skin tone that has the color issue.