The create rainbow function may have a "bug" which causes the White/Black 4th circle in to not have "blue" shade of style(???)

I modified the for loop to i <= 255, instead of i<255, and now the 4th circle has a "blue" style, BUT it is too intense.
Maybe the sigmoid equations need to slightly modified???
Due to my ignorance of the sigmoid equations, whether or not this is a bug is unclear.

Karsten's (?) create rainbow function is located in nodeeditor extension/libs folder, inside basicfunctions.js.
The function is called by setStyle node.

- Brian