Hue Saturation Brightness (0)

HSB: hue, saturation , and brightness
This scheme provides a device -independent way to describe color . HSB may be the most complex scheme to visualize, especially since color selection software has to reduce its three descriptive dimensions to two dimensions on the monitor screen . But once learned, it can be useful in many instances.
The easiest way to visualize this scheme is to think of the H, S, and B values representing points within an upside-down cone . At the edge of the cone base , think of the visible light spectrum (preceeding page), cut from the page and pasted into a circle with shading added to smooth the transition between the (now joined) red and magenta ends.
• Hue is the actual color. It is measured in angular degrees around the cone starting and ending at red = 0 or 360 (so yellow = 60, green = 120, etc.).
• Saturation is the purity of the color, measured in percent from the center of the cone (0) to the surface (100). At 0% saturation, hue is meaningless.
• Brightness is measured in percent from black (0) to white (100). At 0% brightness, both hue and saturation are meaningless.
Brightness as it is described here refers only to relative values within a source that we are looking at (for example, a display screen or printed document ). The actual luminance (of a light source) or reflectance (of an object ) is a different issue— these values are measured with devices such as photographic light meters. The distinction between levels of brightness is actually logarithmic, not linear as the HSB scale would imply.