Adjust color saturation in image areas

The Sponge tool subtly changes the color saturation of an area. When an image is in Grayscale mode, the tool increases or decreases contrast by moving gray levels away from or toward the middle gray.

Select the Sponge tool .
Choose a brush tip and set brush options in the options bar.
In the options bar, choose the way you want to change the color from the Mode menu:
Saturate

Intensifies the color’s saturation
Desaturate

Dilutes the color’s saturation
Specify the flow for the Sponge tool.
Select the Vibrance option to minimize clipping for fully saturated or desaturated colors.
Drag over the part of the image you want to modify.