Apple Color 1.5 - Manual (Page 34)

The HSL Color Space Model Explained
The HSL color space model is another method for representing color and is typically used
for user interface controls that let you choose or adjust colors. HSL stands for hue,
saturation, and lightness (roughly equivalent to luminance) and provides a way of
visualizing the relationships among luminance, hue, and saturation.
The HSL color space model can be graphically illustrated as a three-dimensional cone.
Hue is represented by an angle around the base of the cone, as seen below, while
saturation is represented by a color’s distance from the center of the cone to the edge,
with the center being completely desaturated and the edge being saturated to maximum
intensity. A color’s brightness, then, can be represented by its distance from the base to
the peak of the cone.
Color actually provides a three-dimensional video scope that’s capable of displaying the
colors of an image within an extruded HSL space, for purposes of image analysis. For
more information, see
The 3D Scope .
34 Chapter 1 Color Correction Basics