Setting the Image's Saturation Level
Setting the image's saturation level is the last step in the color correction routine. It is difficult to adjust saturation with Curves, so we use the Hue/Saturation adjustment. It is important to be conservative in your use of the Saturation adjustment to avoid changing the previously set white point, black point, mid tone point, 1/4 & 3/4 tone points, and individual channel adjustments. We do not want to undo the good we have done. This is a visual adjustment and is the only step that has no relation to the RGB values. The Hue Saturation adjustment works with a scale that goes from -100 to +100. Unfortunately, these numbers are out of context with ink percentage or RGB information.We recommend a useful range from -10 to +10 for most images. It is easy to over saturate your images, use caution!
The Hue, Saturation, and Lightness Dialog Box.
Go Layer, New Adjustment Layer, Hue/Saturation.
Make sure the Mode is set to Normal.
Visually adjust the saturation until it appears realistic. If you are in doubt, leave it as it is.