Colorize Filter

The Hue/Saturation command lets you adjust the hue, saturation, and lightness of the entire image or of individual color components in an image. Adjusting the hue, or color, represents a move around the color wheel. Adjusting the saturation, or purity of the color, represents a move across its radius.

A. Saturation B. Hue C. Brightness D. All hues

You can also use the Colorize option to add color to a grayscale image converted to RGB, or to an RGB image--for example, to make it look like a duotone by reducing its color values to one hue.