The Hue/Saturation command in the Adjust section of the Image menu allows you to edit colors using the Hue Saturation Brightness (HSB) model.
Basically, you can take either all the image colors together or select a single color, then change the hue, saturation or brightness accordingly.
In the "Hue/Saturation" dialog there are sliders for the hue, saturation and lightness (brightness). The setting is always 0 for each of these when you first enter the dialog. You can move the sliders through -180 to 180 for Hue, and between -100 and 100 for Saturation and Lightness. These are measured relative to the current setting. (Note that the Hue values can be imagined as being degrees on a circle, so that -180 and 180 result in the same color being selected.)
On the left of the dialog there is a list of all the colors in the RGB and CMY scales. Any one of these can be selected and changed in its hue, saturation or brightness. The default setting is Master, that is , all the colors of the image are changed together.
The Hue slider takes a selected color - or all the colors together - through the range of colors in the RGB/CMY scales. Once the slider position is set the relevant image colors change to reflect the new hue settings. Note that when you next enter the dialog the color list is returned to its normal setting, ready for you to make more changes should you need to.
The Saturation slider increases or decreases the intensity of colors (or a selected color). Decreasing the saturation causes color to become grayer; increasing the saturation causes color to become brighter.
The Lightness slider increases or decreases the brightness of colors (or a selected color). Decreasing the lightness causes color tones to become darker; increasing lightness causes them to become whiter.
All the changes you make in the "Hue/Saturation" dialog are immediately applied to the image on screen. Click on OK to exit the dialog and keep the changes; otherwise click on Cancel to close the dialog and abandon the changes.
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