Read also the first response to this blog about Newton's contribution.

I'm quoting it. It's really damn interesting:

Jeffrey Ventrella on May 8, 2012 at 6:39 pm said: Dr. David Burton, Professor of Art Education at Virginia Commonwealth University, tells me that he’s been lobbying for a variety of color systems to be taught in schools, to reflect the diversity of influences, practices, and historical contexts for color theory. Regarding my blog post on color wheels, He provided the following extra background information:

” Legend has it that Isaac Newton created the first color wheel. As you recall, he did the classic experiment of breaking white light into 7 colors (ROY G BIV–Red, orange, yellow, green, blue, indigo, violet; he really only saw 6) by placing a prism in front of a beam of light coming through a slit in his curtain. Having just a slit of light is essential. If the beam is any wider, overlapping spectra recombine into white light again. Anyway, you are right, violet/red-purple, does not appear in the physical spectrum because red and indigo (purple) are at opposite ends of the spectra.

Why then, violet? Descartes had arranged the 7 notes of the musical diatonic scale into a disc/wheel, probably to demonstrate how octaves follow one another. Newton mimicked Descartes circular format, joining the two ends of the spectrum with a credible hybrid, violet. (Of course, he didn’t see this in his visual spectrum, nor do we, but we have nevertheless labeled it “ultraviolet.”) To his credit, Newton gave each of the color as much proportional room on the wheel as they have in a spectrum–yellow is just a sliver, red is much wider. Also, remember Newton was a numerologist and 7 is a sacred number. Newton published all this in his Opticks (1704). The experiments has been done 20 years before.

Curiously, most color wheels have an even number of colors–6, 8, or 12. This is so complements can sit opposite each other, red across from green. Of course, blue-green is the true complement of red, but that is another story related to the history of pigments. The oldest color wheel I know of is attributed to Anthansius Kirchner (1671, before Newton). It had 5 primaries and 10 secondary colors. Kirschner was also a numerologist and his color wheel has more to do with astrology and numerology than color theory. Most of the colors wheels that followed had 3 primaries (RYB) and 3 secondaries (OGP). After Newton, the most influential color theorist was the poet Goethe with 3 primaries and 3 secondaries.

Munsell (1898) has 5 primaries and 5 secondaries. His color wheel is closer to the truth in that each primary (red) is located opposite of its true visual secondary (blue-green).

I can't believe that for all the time I spent in art and physics classes, I've never been in a lecture that discusses this subject.

I am left wondering at what other apparently physical phenomena are invented by our mind in order to create a continuum. This must happen in sound. Taste as well. What about emotion?