The HSL model is based on how the human eye perceives color using the characteristics of hue, saturation, and lightness. Each characteristic is assigned a value from 0 to 255. The three characteristics are described as follows:
Hue The color reflected from an object, such as red, yellow, or orange. Each hue value is assigned based on its position on the color wheel. On the Jasc Color Picker’s Color wheel, colors are assigned counter-clockwise from the top. Red is at the top (value 0) and as you move around the wheel the colors go through orange, yellow, green, blue, purple, and back to red.
Saturation The purity or vividness of the color. Saturation represents the amount of grey in the color, from 0 (entirely grey) to 255 (fully saturated color).
Lightness The perceived amount or intensity of light in the color. Lightness ranges from 0 (no light, or black) to 255 (total lightness, or white). At 50 percent lightness, or a value of 128, a color is considered pure. For example, pure red has a hue of 255, a saturation of 255 (100 percent) and a lightness of 128 (50 percent). For pure blue, the hue is 170, saturation is 255 and lightness is 128.
Understanding Color and Color Models
How Monitor and Print Colors Differ
Making a Palette Color Transparent