Interesting. Green/blue is missing from negative system, but,

[Alkhemist]

Here is another clue:

The sixth-density of a whiteness which contains a golden quality as you would perceive it; these colors having to do with the blending into wisdom of the compassion learned in fourth-density, then in sixth the blending of wisdom back into an unified understanding of compassion viewed with wisdom. This golden color is not of your spectrum but is what you would call alive. (S33:Q20)

My impression is that the system of chakra colors is a great deal different on the higher densities, which may make determining rays beyond 3D-4D rather difficult(?)