Colour Grading: RGB and Hue Curves > Modifying Red, Green, and Blue Channels > Modifying Hue, Saturation, Luminance, and Lightness >

# Modifying Image Lightness

Increase or decrease the lightness in specific colour ranges or across the image.

To modify image lightness:

1. Indicate the colour grading stage at which the curve modification is being applied:
   - To work on the initial primary grade, click Input.
   - To make curve modifications for secondary colour grading, enable a secondary layer.
2. Click Hue and then click Light to display the Lightness curve.

   The Lightness curve is plotted to the hue spectrum.

3. Sample the colours you want to use as a reference for your adjustments.

   A vertical line representing the reference colour is plotted on the Lightness curve.

4. To select a vertex, click it. To select several vertices, draw a selection box around them.
5. Modify the lightness:
   - To increase the lightness of the colour displayed in the hue spectrum, drag selected vertices up.
   - To decrease the lightness of the colour displayed in the hue spectrum, drag selected vertices down.
   Tip You can also select a vertex to use tangent handles to adjust the curve.
6. To move several selected vertices, select them and then drag one. To restrict vertex movement to the Y axis, press Shift while moving the mouse. To restrict vertex movement to the X axis, press Shift+Alt.
7. To add a vertex to the curve, place the cursor over the area on the curve where you want to add the vertex and then press A. To lock the curve in place while adding a vertex, press Shift+A on the curve.
8. To delete vertices, select them and then press D.
9. Edit the curve until you are satisfied with the results.