"There are four primary colors" -LW Red, Yellow, Blue, and Green! I am not sure ow this relates to an octahedron, but maybe the tetrahedron. I was shopping for a new tv with my girlfriend and one of the selling points was that some new tvs had yellow in addition to the three usual colors. And the picture was much more vibrant in color. If a triangle can describe a circle, then a tetrahedron can describe a sphere. The thing is that the Cartesian 3D makes one think 3D is described by three axes. But we still do not leave i behind us, nor introduce constructable cubic roots. With 4 axes, that is exactly what happens. It does not seem that this changes 3D color space, but obviously what we can do with color, generally. Oh, and maths. thoughts? -- He lived a wonderful life. ========================================== Need Something? Check here: http://ludwig.squarespace.com/wittrslinks/