Colors we can't see

I was struck by the snippet on many-eyes.com, the website created by the Visual Communication Lab (part of IBM's Collaborative User Experience research group) for the express purpose of letting people experiment for free with some of the latest graphing technology and exchange ideas about the underlying data.

I am sensitive to visual discussions being in the middle of one about color and waves with my recently diagnosed as colorblind (sorry - deficient) son.

Concurrently, we were reading Null Hypothesis about the problematic existence of magenta. in my film career, I studied color and light and it seems obvious in retrospect that we overlaid so much of the physics with complete and utter subjectivity.

I've always felt that color is an unknown world, really another dimension. I look forward to reading Goethe's 'Theory of Color" opposing Newton's physical theory.

When did we fall into the trap of a visual representation of a low to high series as being on a wheel? circular? There is no such color as magenta. We have created a connection to close the circle.

ps. more recently I've been told that we have 7 colors in the spectrum because 6 was the devil's number. This was at a gifted children's seminar.