While i did not read Jon's post as snotty, i can see how it can be read
that way. It struck me more as a "did you know of this(?), which seems
like it would be helpful".
Thanks. It was offered in that vein.
The funding of accurate human color perception _measurement_
dates back at least to the time when colored house paints
began to be sold (by Sears, for example) as something to
'spruce up' homes. (Turn of 19th to 20th century, roughly.)
Customers would buy a 'brown' for an addition, hoping to get
the same 'brown' they ordered two years before, and getting
something that 'any idiot' could see wasn't even close. The
control of paint chemicals and dyes wasn't sufficient by
itself at the time and there was a strong need for some
"feedback" to help adjust the dyes, as appropriate.
This commercial desire played into a university research
desire regarding color blindness and provided a substantial
funding source for this research to proceed.
A method was needed so that a 'brown' paint bought today and
used on the shady part of a home would look the same as the
same 'brown' paint bought next year and used on a well-lit
side. Side by side, the two paint jobs should "look the
same" to a viewer -- VERY WIDELY varying lighting conditions.
The CIE color system has remarkable fidelity for that
purpose. It also can deal with lighting conditions within
some limits.
What it does not do is cope with the surroundings, which in
human perception is very important. That is one reason why I
pointed him at Edwin Land and one reason why I wondered how
Charlie was determining when the color reading was wrong or
right.
If you take a canvas and place it on a painting easel and put
swatches of colors nearby each other on that canvas and light
it with a bright 100W tungsten bulb, people will see the
colors a certain way. Then, as you dim the bulb down, the
Planck radiation curve emitted will shift dramatically in
wavelength -- all of us here are well aware of this fact --
causing reflections and the resulting distribution of
wavelengths from the surfaces to be markedly different than
before. Yet even operating at 10W or even 1W of output, with
the distribution almost totally different than before, a
human will still "see" the same "colors."
Do the same experiment, now instead with a cover sheet that
blocks out all but one selected color swatch and the human
will NO LONGER see the same colors when the lighting is
changed. This proved that the human vision system uses the
reflections from nearby areas to help adduce any nearby
color. As the reflections shift dramatically for one color
swatch, so it also shifts for others nearby. Lose that
additional information source and the brain can't maintain
the perception. Keep it, and it can.
Edwin Land spent years studying this phenomenon well after
both CIE standards groups put out their results and it turns
out that humans also use nearby colors to "calibrate" their
perceptions.
In any case, it is VERY illuminating to study this material
(the CIE _and_ Dr. Land research papers) and it _may_ bear on
this "issue." It made sense to me to at least ask if the OP
is fully familiar with the existing research here.
I spent some years working with OSRAM on these issues. I
worried that Charlie may be fighting an issue that might be
more easily 'understood' from a different domain. He is in a
better position to generally know one way or another, but a
small pointer might help if he wasn't already aware.
Jon