Using Masks and Layers—Painting, Filling, and Color Tools - GIMP 2.6 for Photographers: Image Editing with Open Source Software - page 241

3.9.6 Changing the Color of an Image Object—
the Hue-Saturation Function
Hue-Saturation is an extremely flexible tool. It can be used to completely change
an image's color scheme, increase the saturation of one or more colors, create
shades of gray by intensifying or decreasing color, or adjust the color of a selection.
You can even use the Hue-Saturation slider to easily colorize old black-and-white
photos or add color to new black-and-white photos to produce an artsy, nostalgic
effect. In the following exercise, you'll use Hue-Saturation to dye your Easter eggs.
Activate the layer that you wish to modify. Choose Colors > Hue-Saturation .
Click the Master button in the center of the color rectangles. You can move the
Hue slider in the Adjust Selected Color control box to change the hue of the
selected object. Moving the Saturation slider will either intensify the colors in
the image or reduce them (until it becomes a grayscale image). To correct the
image's (LAB) lightness, move the Lightness slider.
Figure 3.60
The options for the Hue-Saturation menu item