In this area, you can color correct LAB values: Luminosity, Saturation and Contrast.
LAB corrections are applied during color management, but before conversion to the output space. LAB corrections will preserve the neutrality of gray scales. To adjust a color, move its cursor to the left or to the right. You can also manually enter a positive or negative value on the far right.
Be careful, if there is no corresponding ICC profile for your print configuration (if any of the resolution, media, mode or quality is displayed in red in the Print module interface), you will not be able to perform a LAB Correction.