The hue of a color places it on the color wheel where the color spectrum (rainbow) is evenly spaced. Each hue corresponds to a particular wavelength in the portion of the electromagnetic spectrum that is visible to the human eye.

## Electromagnetic Wavelength

Here are the approximate range of wavelengths (in angstroms) for each of the usual rainbow hues:

• Violet 3900-4550
• Blue 4550-4920
• Green 4920-5770
• Yellow 5770-5970
• Orange 5970-6220
• Red 6220-7700

## Color Wheel Basics

 Here is a common color wheel with 12 hue gradations. There can be more or fewer gradations. Primary hues are red, yellow, and blue. See Systems for a discussion on additive and subtractive primaries. Secondary hues are formed from the primary: orange (red+yellow), green (yellow+blue), violet (blue+red). Intermediate hues (tertiary) are formed from adjacent primary and secondary colors, eg yellow-green is formed from yellow (a primary color) and green (a secondary color). Cool hues range from green to violet. Warm hues range from red to yellow. Analogous hues lie side by side on the color wheel, eg red, red-orange, and orange. Complementary hues lie directly opposite of each other on the color wheel. EG: Red and green.

## Hues of Color Systems

In the color wheel, the primary hues are RYB (red, yellow, and blue). These hues are subtractive (removing colors brings it closer to white) in this manner:

In most print, the primary hues are CMY (cyan, magenta, and yellow). These hues are subtractive (removing colors brings it closer to white) in this manner:

In most video, the primary hues are RGB (red, green, and blue). The hues are additive (adding colors brings it closer to white) in this manner:

The Munsell color system specifies hues on the color wheel using 3 notations:

• 0-100 starting just before red.
• number (usu. 2.5, 5, 7.5, 10) and 10 "principal hues" (R, YR, Y, GY, G, BG, B, PB, P, RP). EG: 5R.
• N indicates no hue. EG: pure white.

The Ostwald color system specifies 24 hues on the color wheel. The 8 groups are yellow (1,2,3), orange, red, purple, blue, turquoise, seagreen and leafgreen.

Page Modified: (Hand noted: ) (Auto noted: )