Munsell Color System

The observation of complementary colors is further expressed in the Munsell color system developed by Professor Albert Munsell of the Massachusetts Normal Art School in the early 20th century. Professor Munsell divided color into three dimensions and applied a numeric formula to express colors. The three dimensions of colors are:

Hue: Loosely defined as the color (i.e. Red, Yellow, Green, Blue and Purple)
Value: Lightness (i.e. how dark the color is on a black to white scale)
Chroma: Purity or saturation of the color.

Each of these dimensions is expressed on a scale for which hue is measured by degrees around horizontal circles, chroma is measured radially outward from the neutral gray axis and value is measured vertically from bottom (0 - black) to top (10 - white).

Complementary colors are defined as any two colors that have the same value and chroma, and lie opposite each other on the hue scale.

This color system is most easily understood visually in the diagram below. This color system has been adopted in dentistry to form the basis of most shade guide systems including the popular Vita Classic and Vita 3D Master Shade Guides.



Portions of this post were adapted from the book:
Fundaments of Color - Shade Matching and Communication in Esthetic Dentistry published by Quintessence Publishing Co. Inc and written by Dr. Stephen J. Chu, Dr. Alessandro Devigus, Dr. Rade D. Paravina and Mr. Adam J. Mieleszko. and the
Wikipedia article/s:
http://en.wikipedia.org/wiki/Munsell_color_system