I notice that you make the same mistake in your article as most people do about the 'rainbow'.
Sir Isaac Newton was many things, and one of them was a mystic. He believed that numbers were 'magic' - in particular, the number seven.
When he examined the continuous spectrum of light he actualy only discerned six colours: Red, orange, yellow, green, blue, violet.
He felt this was wrong. To maintain number harmony in creation he believed there should be seven colours and so invented 'Indigo'. He even invented the name.
Indigo does not exist in the spectrum but generations of people, having grown up being told it was so, believe it to be real.
What I have said is verifiable fact, if one chooses to do research*.
There are also one or two other inaccuracies in your 'article'.
As, indeed, there were in your little essay on composition.
Perhaps if you actualy came onto the board proerly to discuss these matters rather than just posting links to your website?
*I am lucky, being situated only 10 miles from the house where Newton lived and worked. It is a museum - and still has the original apple tree in the garden.