While Edit mode tools allow you to make a variety of global adjustments to your images, and the Edit brush makes it possible to adjust specific sections of your image, Pixel Targeting allows you to target distinct tones, colors, and skin tones. You can select a number of Edit mode adjustments and apply them to a photo's individual colors or tones, or just to skin tone, by using Pixel Targeting. For example, when you open an image in the Exposure tool, the exposure is adjusted over the entire image. However, if you want to only adjust the exposure of the blue sky in the image, you could use Pixel Targeting to target the color blue, and thereby only increase the exposure on the sky.
To Perform Targeted Adjustments with Pixel Targeting:
The Pixel Targeting panel consists of four sections: Targeted Tones, Targeted Colors, Skin Targeting, and the Target Mask.
Target Mask:
The Target Mask allows you to see the areas in the image that are targeted by displaying them in white. When no pixels are targeted, the Target Mask will appear completely black. Conversely, when all pixels are targeted, as is the case before any sliders have been altered on the Pixel Targeting panel, the entire Target Mask will appear completely white.
Targeted Tones:
The Targeted Tones sliders allows you to target tones of brightness for adjustment. To target one or more tones, you may find it easiest to press the Min button under the Targeted Tones section. This deselects all tones, and you can then select specific tones to target by moving their sliders up between 0 and 100, depending on your desired intensity.
Targeted Colors:
The Targeted Colors sliders allows you to target specific colors for adjustment. To target one or more colors, you may find it easiest to press the Min button under the Targeted Colors section. This deselects all colors, and you can then select specific colors to target by moving their sliders up between 0 and 100, depending on your desired intensity.
Skin Targeting:
The Target Skin slider allows you to specifically target skin tones for adjustment. To target skin tones, move the slider to the right between 0 and 100, depending on your desired intensity.
When you move the Skin Targeting slider, all other colors (except for skin tones), are excluded. You cannot then alter the green color slider, for instance. You can, however, further fine-tune your skin color adjustment with the yellow and orange sliders, as well as the tones sliders that are within the brightness range of the skin color you are adjusting. If you would like to target skin and another color, you will need to perform skin targeting, configure the Edit mode tool as desired, and apply the Edit mode tool by pressing Apply. Then use the Pixel Targeting panel to target the additional color(s).
To exclude skin tones from your adjustments, move the slider to the left between 0 and -100. You can use this method to ensure that, while applying adjustments with a variety of Edit mode tools, the skin tones will remain untouched.
You can right-click a slider to reset to the default value.
Pixel Targeting becomes even more powerful when paired with Selections or the Edit Brush. These tools in combination with Pixel Targeting make it possible to target very precise areas, such as only the blue of a person's eyes, rather than all of the blue in the image.
Click Reset to clear your changes and reset to default settings. 
You can save your settings as a preset for future use. Using the Save Preset button on the Pixel Targeting panel will only save your pixel targeting settings, and not the settings on the Edit mode tool you are using. Those must be saved separately.