Hue
Adjust the slider to change the color teint of the image. This control is quite sensitive so handle with care.
Saturation
Adjust the slider to the left to saturate the colors with white, and slide to the right to desaturate. Sliding the bar completely to the right means you will get a grayscale image.
Lightness
Adjust to the right to increase lightness (lighter image) and to the left for opposite effect.
H/S/L are adjusted for each pixel in the image so this operation may take a bit of time for large images.
Tip: tune the Internal Rendering DPI (User panel) down before adjusting H/S/L on large photos. A lower value there (e.g. 70) will speed up the adjustments. Later on you can always tune it up again. No image information gets lost, because the original remains in the document file.