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Perception, reality, and the color wheel
Topic Started: Jul 14 2011, 08:07 PM (438 Views)
Horace
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HOLY CARP!!!
I thought some of you might like this.

Red.

It's always been my favorite color. Not sure why. But apparently it's the only color that is in fact two different things.

Ever seen a "color wheel"? Of course you have. Here's one:

Posted Image

Notice how red is right next to orange and violet.

Ultra-violet and infra-red are the key words here - violet and red are the limits of the visible spectrum. Violet and red have NOTHING to do with one another in reality. They are OPPOSITES in reality.

But perceptually, they blend together. Violet contains red - it is blue + red. How can red appear at opposite ends of the color spectrum? How can it be both low and high frequency visible light?

I was just thinking about that today when it came up randomly in a conversation with an extraordinarily intelligent co-worker of mine. He told me that the "red" receptors in our eyes respond not only to low-frequency visible light but also high-frequency light. The "red" cones have two completely separate response curves, one on the low end and the other on the high end. I could have crafted a better post out of this but I won't google it. This is just what I talked about today. I wish I could have included some graphics about this new stuff that I'm thinking about.'

Evolution wanted a continuous color spectrum. That low/high frequency thing about "red" allows us to construct a color wheel. It makes "color" a continuous perception. Why is that? Color blind people aren't really disabled in any way - so color continuity doesn't seem like something that would be that advantageous. Why would evolution have wanted that continuity?

Interesting??? (I think so.)
As a good person, I implore you to do as I, a good person, do. Be good. Do NOT be bad. If you see bad, end bad. End it in yourself, and end it in others. By any means necessary, the good must conquer the bad. Good people know this. Do you know this? Are you good?
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Catraoine
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Junior Carp
I heard that there is really no such colour as 'white' but it is actually a combination of all colours which our brains cannot identify so we only see what is called' white', do you know how true that is?
Hatred is often felt by those that cannot understand why you are so loved.
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kenny
HOLY CARP!!!

Nature did not place the colors in a wheel.
Humans did.

A prism disperses the colors of the spectrum in a line. Posted Image

But yes it is interesting and curious how handily they fit into a wheel, and how the wheel conveys the opposites, the relationships and the mixing.
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kenny
HOLY CARP!!!
Another related thing I've wondered about, the 3 primary colors for mixing light are different than the 3 for mixing pigments.

Light: Red Green and Blue
Pigments: Red Green and Yellow.

Why are they different?
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Red Rice
HOLY CARP!!!
It gets even more complicated when you remember that you have to distinguish between additive and subtractive color models. For example, when talking additive colors, white is the combination of red, green and blue. On the other hand, white is also the absence of subtractive colors.
Posted Image




Civilisation, I vaguely realized then - and subsequent observation has confirmed the view - could not progress that way. It must have a greater guiding principle to survive. To treat it as a carcase off which each man tears as much as he can for himself, is to stand convicted a brute, fit for nothing better than a jungle existence, which is a death-struggle, leading nowhither. I did not believe that was the human destiny, for Man individually was sane and reasonable, only collectively a fool.

I hope the gunner of that Hun two-seater shot him clean, bullet to heart, and that his plane, on fire, fell like a meteor through the sky he loved. Since he had to end, I hope he ended so. But, oh, the waste! The loss!

- Cecil Lewis
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kenny
HOLY CARP!!!
If you mix the 3 primary light colors you get white light.
If you mix the 3 primary pigment colors you get black.
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Horace
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HOLY CARP!!!
kenny
Jul 14 2011, 08:42 PM
If you mix the 3 primary light colors you get white light.
If you mix the 3 primary pigment colors you get black.
That is because pigment colors (paint and the like) are defined by the colors they absorb, while light colors are defined by the light itself.

Red paint absorbs all light other than red. Red light is simply red light. It contains nothing but red light.

Paint and light are different fundamentally. We ascribe "color" to them but that means very different things between them.
As a good person, I implore you to do as I, a good person, do. Be good. Do NOT be bad. If you see bad, end bad. End it in yourself, and end it in others. By any means necessary, the good must conquer the bad. Good people know this. Do you know this? Are you good?
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Horace
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HOLY CARP!!!
Catraoine
Jul 14 2011, 08:18 PM
I heard that there is really no such colour as 'white' but it is actually a combination of all colours which our brains cannot identify so we only see what is called' white', do you know how true that is?
White is a color as any other color, but it is not a primary color. In our eyes, we have "cones" of three different types, which respond to three different wavelengths of light. Red, green, blue are the colors we respond to. If a combination of red and blue receptors respond to a certain stimulus, we see red+blue, which is violet. This is all in our brain's software. "White" is all three colors at the same time. It is a color, if only a limit of color.
As a good person, I implore you to do as I, a good person, do. Be good. Do NOT be bad. If you see bad, end bad. End it in yourself, and end it in others. By any means necessary, the good must conquer the bad. Good people know this. Do you know this? Are you good?
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Horace
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HOLY CARP!!!
kenny
Jul 14 2011, 08:42 PM
If you mix the 3 primary light colors you get white light.
If you mix the 3 primary pigment colors you get black.
Because in one case you are mixing plus signs, in the other case you are mixing minus signs.
As a good person, I implore you to do as I, a good person, do. Be good. Do NOT be bad. If you see bad, end bad. End it in yourself, and end it in others. By any means necessary, the good must conquer the bad. Good people know this. Do you know this? Are you good?
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Red Rice
HOLY CARP!!!
kenny
Jul 14 2011, 08:27 PM
But yes it is interesting and curious how handily they fit into a wheel, and how the wheel conveys the opposites, the relationships and the mixing.
It's because of the way our eyes are constructed and the way we perceive color. The cones in our eyes respond to red, green and blue light, but also overlap in their responses, so we are able to combine the input in our brains to see many different colors, in addition to responding to individual wavelenghts. For example, there are two ways our eyes can see purple light:

1) Shine an equal amount of red and blue light into the eye. The red light will stimulate the red cones, the blue light will stimulate the blue cones, and the brain will combine the input into the color purple. Note that the wavelength of both red and blue light is longer than the wavelength of purple light, so the red and blue wavelengths are not able to "combine" in any way that results in a purple wavelength.

2) Shine the purple wavelength of light into the eye. Red and blue cones overlap in their response to this wavelength, so both will be stimulated, and again the brain will combine their input into the color purple.

So the fact we can perceive a linear spectrum as a circular wheel is a function of the way our eyes and brain process color.
Civilisation, I vaguely realized then - and subsequent observation has confirmed the view - could not progress that way. It must have a greater guiding principle to survive. To treat it as a carcase off which each man tears as much as he can for himself, is to stand convicted a brute, fit for nothing better than a jungle existence, which is a death-struggle, leading nowhither. I did not believe that was the human destiny, for Man individually was sane and reasonable, only collectively a fool.

I hope the gunner of that Hun two-seater shot him clean, bullet to heart, and that his plane, on fire, fell like a meteor through the sky he loved. Since he had to end, I hope he ended so. But, oh, the waste! The loss!

- Cecil Lewis
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Red Rice
HOLY CARP!!!
kenny
Jul 14 2011, 08:42 PM
If you mix the 3 primary pigment colors you get black.
Actually, you get brown or gray. You can never get black by mixing primary pigment colors.
Civilisation, I vaguely realized then - and subsequent observation has confirmed the view - could not progress that way. It must have a greater guiding principle to survive. To treat it as a carcase off which each man tears as much as he can for himself, is to stand convicted a brute, fit for nothing better than a jungle existence, which is a death-struggle, leading nowhither. I did not believe that was the human destiny, for Man individually was sane and reasonable, only collectively a fool.

I hope the gunner of that Hun two-seater shot him clean, bullet to heart, and that his plane, on fire, fell like a meteor through the sky he loved. Since he had to end, I hope he ended so. But, oh, the waste! The loss!

- Cecil Lewis
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Horace
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HOLY CARP!!!
Red Rice
Jul 14 2011, 08:57 PM
kenny
Jul 14 2011, 08:42 PM
If you mix the 3 primary pigment colors you get black.
Actually, you get brown or gray. You can never get black by mixing primary pigment colors.
Why is that, RR? I've seen black pigment. (Or at least it looked black.)
As a good person, I implore you to do as I, a good person, do. Be good. Do NOT be bad. If you see bad, end bad. End it in yourself, and end it in others. By any means necessary, the good must conquer the bad. Good people know this. Do you know this? Are you good?
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Red Rice
HOLY CARP!!!
Oh, you can get black pigment, just like you can get white pigment. You just can't make it by mixing primary colors.
Civilisation, I vaguely realized then - and subsequent observation has confirmed the view - could not progress that way. It must have a greater guiding principle to survive. To treat it as a carcase off which each man tears as much as he can for himself, is to stand convicted a brute, fit for nothing better than a jungle existence, which is a death-struggle, leading nowhither. I did not believe that was the human destiny, for Man individually was sane and reasonable, only collectively a fool.

I hope the gunner of that Hun two-seater shot him clean, bullet to heart, and that his plane, on fire, fell like a meteor through the sky he loved. Since he had to end, I hope he ended so. But, oh, the waste! The loss!

- Cecil Lewis
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Horace
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HOLY CARP!!!
I'm pretty sure that there are no objective definitions of primary colors, white, or black, and thus no defined impossibilities of creating one from the other.

(But I could be wrong.)
As a good person, I implore you to do as I, a good person, do. Be good. Do NOT be bad. If you see bad, end bad. End it in yourself, and end it in others. By any means necessary, the good must conquer the bad. Good people know this. Do you know this? Are you good?
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jon-nyc
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Cheers
Horace
Jul 14 2011, 08:07 PM
Evolution wanted a continuous color spectrum. That low/high frequency thing about "red" allows us to construct a color wheel. It makes "color" a continuous perception. Why is that?
Very interesting question.
In my defense, I was left unsupervised.
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blondie
Bull-Carp
As a quilter, I thought I understood color.
Intuitively, I know I understand color + I have incredible color memory.
Then I read this thread.
Oh boy.
I guess I know squat about color.
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big al
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Bull-Carp
Red Rice
Jul 14 2011, 08:54 PM
kenny
Jul 14 2011, 08:27 PM
But yes it is interesting and curious how handily they fit into a wheel, and how the wheel conveys the opposites, the relationships and the mixing.
It's because of the way our eyes are constructed and the way we perceive color. The cones in our eyes respond to red, green and blue light, but also overlap in their responses, so we are able to combine the input in our brains to see many different colors, in addition to responding to individual wavelenghts. For example, there are two ways our eyes can see purple light:

1) Shine an equal amount of red and blue light into the eye. The red light will stimulate the red cones, the blue light will stimulate the blue cones, and the brain will combine the input into the color purple. Note that the wavelength of both red and blue light is longer than the wavelength of purple light, so the red and blue wavelengths are not able to "combine" in any way that results in a purple wavelength.

2) Shine the purple wavelength of light into the eye. Red and blue cones overlap in their response to this wavelength, so both will be stimulated, and again the brain will combine their input into the color purple.

So the fact we can perceive a linear spectrum as a circular wheel is a function of the way our eyes and brain process color.
Just to make thing a little more interesting, there is significant variablity in the genes that encode the receptor molecules for color vision in the human eye. This accounts for red-green color blindness for those unlucky in the draw, but can also provide enhanced color perception among other, particularly women, since some of the genes are sex-linked.

I recall reading an article in Scientific American a few years ago that indicated that some women have a larger complement of receptor types - four instead of three - than other humans and thereby can discriminate colors that look identical to most of us.

Another article descibed how the eye can be tricked into seeing "forbidden" colors like yellow-blue (not green) and red-green (not brown) which suggests that some color perception thought to be hard-wired in traditional visual theories actually has a "software" component; i.e., some signal processing in the brain before the color is categorized.

Big Al
Location: Western PA

"jesu, der simcha fun der man's farlangen."
-bachophile
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brenda
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..............
Horace, I am very interested in color theory as it relates to fabrics and rug hooking. I love to learn more about this.

Horace, you should be a rug hooker.
“Weeds are flowers, too, once you get to know them.”
~A.A. Milne
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