Each primary and intermediate color was allotted ten degrees around the compass and then further identified by its place in the segment. For example, primary red would be identified as 5R since it stands at the mid-point of the red segment. Munsell's arrangement of colors in this way was also important for his concept of color harmony, or balance. Munsell was a conservative artist with strict views on the aesthetics of painting. He wanted his system to serve not only as guide for notating colors, but as a guide for choosing complimentary colors for artistic work.
Value is a neutral axis that refers to the grey level of the color.
This ranges from white to black. As notations such as 10R, 5YR, 7.5PB, etc. Thus a value of 5N would denote a middle gray, 2N a dark gray, and 7N a light gray. The value of a particular hue would be noted with the value after the hue designation. It should be noted, too, that Munsell's scale of value is visual, or perceptual.