On Tue, 2 Mar 2010 20:20:42 -0800 (PST), Bill wrote:

On Mar 2, 7:41*pm, Jeff Liebermann wrote:

http://www.schoolofcolor.com/acatalog/Blue_and_Yellow.html
* *A pure yellow and a pure blue would make black not green,
* *a pure red and a pure blue would also produce black.

So I can believe School of Color or my own lying eyes...

You can believe your eyes for two different cases of primary color -
transmission (additive) and reflection (subtractive) - and one of
those examples will say your eyes are lying.

Jeff's example can be tested quite simply (and was suggested by Roy).
Take a displayed image (on your computer) of a photo of your swatch of
your two colors, yellow and blue, mixed on a piece of paper in exactly
the fashion of your kindergarten experience. Arrange it so the paper
has yellow and blue margins merging into your green center.

As I said, display your art work on your monitor. Place a very strong
magnifying glass near the display to observe the areas at the pixel
level (I had to use 20X) You will find, true to your experience that
the green pels of the display correspond to the green area of the
mixed colors. You will find blue pels that correspond to the blue
area of mixed colors. However, you will find no yellow pels in the
yellow pigment you mixed with the blue - those pels are red and green.
So, looking at the transmitted light of a reflected light image would
have your eyes witnessing that there was absolutely no yellow in your
original finger paint. The evidence available to your own eyes (and
everyone else) would say that Red+Green+Blue=Green Do you believe
that? It is your own yellow pigment that you took a picture of and
examined on your own computer. Your eyes are lying to you.

Color is an illusion of the mind and nothing else but a convention of
terminology.

73's
Richard Clark, KB7QHC