The Color Wheel

We obtain a color wheel by connecting the two extremes of the color bands and creating a circle. The color wheel serves to demonstrate the connection between primary and secondary colors. The graphics below illustrate the color wheel that results from the additive color mixing model:

The color wheel

Additive color mixing

It makes no difference whether the determination of the color wheel is based on the additive or subtractive color mixing model, because the basic colors are at same angles to each other in both procedures (look again at the direct comparison of both graphics). The RGB as well as the CMY primary colors have an angular separation of exactly 60°.
 
It is somewhat problematic to display colors on the computer screen, and after all, not all colors can be displayed. Following is an example that shows a range of green hues:

When talking about green, we imagine an intense green. But this color cannot be seen in the graphics, although the left square is set to the green value 255, i.e. to maximum. Just take a tube of green oil or acrylic paint and compare it with the screen colors. The green paint is more intense and much more colorful. The same applies to all other screen colors: When they are compared with paints, their colorfulness lags behind.
Even if a single screen color does not correspond to reality: In relations to each other and in combination with the luminous effect of the screen, the colors can produce thoroughly realistic impressions and contrasts.
 
Further color wheels are described on the two following pages.