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VBspeed © 2000-10, updated: 19-Nov-2001
Color Models

RGB vs HSB (aka HSL)
A remark by Branco Medeiros, 1999
'  * The RGB color model represents colors as they are used in light
'  emiting objects, such as the beams in a monitor. In this model,
'  each light beam represents the Red, Green or Blue lights.
'  RGB colors are called "Additive", that is, the frequencies
'  of each light beam are combined to emit the final color.
'  This way, as any beam value is incremented, the resulting color
'  becomes lighter. The white color, for instance, is given by the
'  maximum value of each beam (Red=255, Green=255, Blue=255), and
'  black is given by the absence of light in each beam
'  (Red=0, Green=0, Blue=0).
'  Compare this with the "Subtractive" model (such us the one used
'  in printing and painting and other real life objects that don't
'  emit light): the light that touches a paint spot
'  fires energy in specific frequencies, thus perceived by our
'  eyes as a given color. The practical effect of this is that the
'  color spot "absorbs" all colors but the one that we see.
'  Take, for example, a blue object. We see it blue because it
'  absorbs all light frequencies but the blue frequency (It's
'  funny to think that actually a blue object is any color but blue).
'  In the subtractive model, more quantities of "paint" means darker
'  colors, while less quantities give us a lighter color.
'  * The HSB color model is just a mathematical representation of
'  color, in a way more similar to our color perception.
'  For instance, the HSB model breaks the color into three
'  components: The Hue (which would be the "pure" color), the
'  percentage of Saturation ("how much" color) and the Brightness
'  of the color (also a percentage). The Hue comes in the
'  range of 0 to 360. The HSB model is also called HSL (L is for
'  "Lightness") or HSV (V is for "Value" [!!]).
'  This model comes in handy where the RGB model can't help, for
'  instance, classifying similar colors, classifying colors by
'  levels of darkness, sorting colors, etc.
'  Warning:
'  Because of the differences between the two color models,
'  converting between RGB and HSB values is not a transitive
'  operation, that is, given an RGB value converted to HSB, when
'  converting back to RGB the result may be different from the
'  original. And Vice-versa.
'  This is "by design"... ;-))

Check Branco's site for more (incl. cool code): The HSB Color Model