Phobos colour module?

[via Digitalmars-d]

On Tuesday, 6 January 2015 at 08:52:06 UTC, Ola Fosheim Grøstad 
wrote:
> - with negative values you can then have a unique 
> representation of a single colour in CIE (the theoretical base 
> for RGB that was developed in the 1930s).

Actually, what I refer to here is a model of how humans perceive 
colour:

http://en.wikipedia.org/wiki/CIE_1931_color_space#CIE_standard_observer