Another thing to note about the modified CEI chromacity diagram to the right is that it represents the colors attainable with modern printing inks, not the visible spectral colors.

To properly depict the Spectral Colors, the Magenta color would need to be replaced with an appropriate "Grey Scale", as the Magenta shown is the Complement of Green,- a mix of Red11 and Violet11, rather than a mix of Violet11 and Red12 which is invisible. A subdued Magenta could be used in place of a gray scale to indicate this color is not as visible as the others.

Finally, the diagram only depicts the one and only Visible Spectral, S11. All the other spectrals should have all their colors subdued to indicate they have no visible colors. That is if there is any point in diagraming any of the other spectrals.

I have detailed the standard CEI System and how to use it, elsewhere at this site. This brings up the fact that up to now I have been concentrating on only one of the three properties of color, its Hue. Color has two more properties, Intensity, and Chroma. A color's hue is its wavelength. A color's Intensity is measured as the magnitude of the electromagnetic disturbance or light wave.