Daniel Carrera wrote:
On Sun, Mar 30, 2003 at 05:19:35PM +1000, Fay wrote:
Hi Daniel,
I don't think that either set of colours has to do with how our eyes work.


Actually, it does. Recall: - Colours are frequencies of light. - White is the sum of all frequencies, and black is no frequency. - The human retina has cones for red green and blue.

[...]


If you mix red and green light you get yellow.

If you mix red and green light your retina perceives all colours except blue, which is equal to yellow (see above).

That's not quite the way I would have put it. Your eye has cones that have different frequency responses roughly forming normal curves centered on red, green, and blue. (See <http://hyperphysics.phy-astr.gsu.edu/hbase/vision/colcon.html#c1>) If your eye really _just_ saw the red, green, and blue, you would be unable to see actual yellow light; I guess you'd sort of see on three axii rather than a spectrum of color, if that makes sense. But it doesn't work that way, so a certain wavelength of yellow can be faked with certain levels of the peak sensitivies. It's indistinguishable by eye. (Unless you're a tetrachromat. <http://www.redherring.com/mag/issue86/mag-mutant-86.html>)


That aside, I think you're correct...and your grade school teacher lied. Sorry. ;)

Scott Lamb

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