Where are the Purples? Where is Magenta?
The color spectrum that we've all seen in rainbows and other light phenomena, has no purples. And not only that, while one can find a color complement of red (cyan), orange (blue) and yellow (violet), there are no visible color complements of green.
The visible color spectrum extends from short wavelength violet to long wavelength red:
But all of these colors are missing:
The reason is that the purples do not exist as single-wavelength colors. Rather, they are the additive mixture of two colors - red and blue. And, it turns out that these purples are exactly the mssing complements of the spectral greens!
So only about 70% of the colors in a color wheel are spectral, the other 30% are non-spectral color mixtures.