From: Geoff Ruth (geoffreyruth@usa.net)
Date: Wed Dec 08 1999 - 20:34:17 PST
Message-ID: <19991209043418.13029.qmail@www0s.netaddress.usa.net> Date: 8 Dec 99 20:34:17 PST From: Geoff Ruth <geoffreyruth@usa.net> Subject: Re: [pinhole color]
> But what is happening with your cones when
> you see gray, brown, or neon colors?
I'll take a stab at Amy's first question. It's still the red, green, and blue
cones firing with different strengths that let you perceive "weird" colors
like gray or neon. Here's how I think of perceiving gray: When you perceive a
dimly lit black, almost none of your cones are firing, while when you perceive
a very well-lit white, almost all of the green, red, and blue cones are
firing. So to see a 50% gray, 50% of the red, green, and blue cones would be
firing. If 50% of the red and green cones were firing, but 100% of the blue
were firing, then you would see a sort of washed-out blue. On the other hand,
if 0% of the red and green cones were firing, but 50% of the blue were firing,
then you'd see a grayish-blue color. Similarly, for other colors like brown or
neon-pink, different combinations of R, G, or B cones would be firing.
If you have a computer, you can demonstrate this to yourself. A simple way to
do this is to take some drops of water and put them on a color computer (or
TV) screen. No matter what the color of the area under the bubble, the water
will refract the R, G, and B electron beams so that you see red, green, and
blue speckles.
A more precise way to investigate this is to use a color picker on a computer.
Since I know Macs, I'll explain how to do it on that platform -- maybe someone
else can tell how to do it on Wintel computers. In System 8.5 or newer, you
can go to the "Appearance" control panel, then click on the "Appearance" tab
and select "Other..." under the "Highlight color" option. Scroll down in the
window that appears until you see "RGB Picker." This will let you adjust the
intensity of red, green, and blue colors that go into making up a color: it's
kind of fun to mess around and try to make different colors by adjusting the
sliders.
-Geoff Ruth
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