Artist 
Writer Munsell color system
A system for organizing color that includes a color wheel to order hues, and a notation system for value and saturation. Values range from 0 (black) to 10 (white). Saturation ranges from 0 (grays) to 14 (pure colors). Therefore, a YR-3-4 represents a dark (value 3) dull (saturation 4) orange, which we usually call brown. A Y-8-12 represents a pure (saturation 12) cadmium yellow, whereas Y-6-6 represents a duller yellow ochre (saturation 6). The Munsell color wheel has ten colors. Its five primary colors are: red, yellow, green, blue, and purple. The five secondary colors are name logically by combining the adjacent two names. The order of colors in a Munsell color wheel is: green-yellows, yellow, yellow-red, red, red-purple, purple, purple-blue, blue, blue-green, and green. I lay out my spectrum palette in this order.
See the Color Building Block for more information.