[OT] Light frequency or wavelength to (eg RGB) colour

[Warren Block]

On Thu, 31 Dec 2015, Ian Smith wrote:

> does anyone know of a method - preferably a formula - for converting
> known frequencies (or complementarily, their wavelengths) within the
> visible spectrum to its colour rendition in RGB, CMYK or whatever?

http://stackoverflow.com/questions/1472514/convert-light-frequency-to-rgb

The first answer supplies as many formulas as anyone might want.  Scroll 
down and there is a Pascal routine to actually do the conversion.