Re: Color Mixing (Pigment) question

[Brian Whatcott <betwys1@SBCGLOBAL.NET>]

At 11:17 AM 5/19/2004, Vickie, you wrote:
> The key to most color mixing is that pigments and color filters pass a broad
> range of wavelengths of light, not just one wavelength of light. The brain
> then takes this mix of wavelengths, averages the spectrum, and interprets it
> as a single "color."  This leads to a lot of confusion because most simple
> explanations don't take the range of wavelengths into account. Mixing blue
> and green averages out to cyan because the spectrum is enhanced in the
> wavelength region where the two colors overlap. If you had a blue filter
> with a very narrow wavelength bandpass, stacked on top of a green filter
> with a very narrow bandpass, so that the two wavelength ranges didn't
> overlap, then these filters would block the light entirely. But particles in
> mixed pigments are more side-by-side than blocking each other, so the
> reflected blue & green colors average.
>
> Vickie Frohne


To Vickie's excellent description, I'd add just two notes:
if you mix house paint, or water colors, a blue pot and a green pot
will not make a black pot.
The cone receptors  are  themselves rather broad band, as a
chart on color sensitivity reveals. I seem to recall that Polaroid's
creator, Edwin Herbert Land, could successfully use two color
 approaches to color prints, to reasonably persuade the eye that
the usual colors were being  portrayed (in many cases) in the
estimation of the differential response of two color specific cone types.

Maxwell, too had observed something of the kind.



Brian Whatcott    Altus OK    Eureka!