The color balance tool modifies the color balance of the active selection or layer.
Selecting one of these options will restrict the range of colors which are changed with the sliders or input boxes for Shadows, Midtons and Highlights.
Sliders and input boxes allow to select colors weights.
This button sets color levels of the selected range back to zero.
This option ensures that brightness of the activ layer or sélection is maintained.
The Preview checkbox toggles dynamic image updating. If this option is on, any change made to the RGB levels are immediately seen on the active selection or layer.