The main problem is that the value component of HSV is just a measure for the physical lightness of color, but not for the perceived brightness. Thus, fully saturated yellow has the same “value” as blue. Beside of this strong hue-dependency of brightness, there is also no linear brightness gradient within a single hue. At this point, you better prepare yourself for some ultimate color geekyness. Click the color-space below to go to Gregor Aisch’s interactive color picker…
Also…
History of Munsell Color System and Scientific application
HSL stands for hue, saturation, and lightness, and is often also called HLS. HSV stands for hue, saturation, and value, and is also often called HSB (B for brightness). A third model, common in computer vision applications, is HSI, for hue, saturation, and intensity. Unfortunately, while typically consistent, these definitions are not standardized, and any of these abbreviations might be used for any of these three or several other related cylindrical models (from Wikipedia)
