why light is consist of seven or more color not only three color?

I think light is only consist of three colors, red , green and blue. And it is not consist of seven color or more.
The reason is when light dispersed by prism, there have overlap by red, green and blue.

If light only have one kind of color, and it through a prism, the result should be below.
View attachment 6887

If light consist of two kind of color.
View attachment 6888

If light consist of three kind of color.
View attachment 6889

We can see that the picture of "If light consist of three kind of color" is very similar to goethe observation in goethe color theory

We know that when three primary color combine, they can form other color.
when red combine with green, it become yellow and when green combine with blue it become cyan.
View attachment 6891

So the result should like that
View attachment 6890

So I think the color we see after light through a prism, yellow is the combination of red and green,
cyan is the combination of green and blue.

if yellow is the combination of red and green, cyan is the combination of green and blue, why the last color is violet not blue.

 

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There aren't 3 types of color -- there are three dimensions of color.

These dimensions may be described in terms of the response of the three types of cones at the back of the eye which are responsible for color stimulus or they may be described in terms of the physiological sensations of X, Y and Z of the CIE 1931 standard observer or they may be described in terms of combinations of three physical R, G, B stimuli or they may be described in terms of hue, saturation and intensity, etc.

In a similar way, three dimensions of spacial location may be described with Cartesian or spherical coordinates.

But it's not true that all color sensations can be generated by just 3 physical primaries, because even the best possible choice of a red, green and blue primaries will not reproduce all the colors of the spectrum.

If you choose 435.8 nm, 546.1 nm, and 700 nm then you will be especially poor at trying to replicate the sensation of 505 nm or 740 nm light. If you choose 435.8 nm, 517 nm, and 740 nm then you will be especially poor at trying to replicate the sensation of 495 nm or 565 nm light. This is because the full physical range of color is a convex shape in three dimensions and no finite number of points in the interior or surface of that three-dimensional solid of possibilities can form a convex hull enclosing all possibilities. This is why the X, Y and Z stimuli of the 1931 standard observer are unphysical colors, useful for their mathematical not physical properties.

http://en.wikipedia.org/wiki/CIE_1931_color_space
http://en.wikipedia.org/wiki/Primary_color

 

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Light has a wavelength. It doesn't really have a colour. Colour is a quale. It's how we interpret light, in our heads.

 

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Further explanation

I want to further explain my assumption. The question "why light is consist of seven or more color not only three color" is only consider the visible light and not include invisible light.

And I think newton made a mistake in his observation in the light through a prism experiment, because he not notice that light has
overlap when dispersed by prism. If only one line of light to through the prism, it sure do not has any overlap between different colored light after dispersed by the prism,
But when a beam of light through a prism it sure has overlap between different colored light after dispersed by the prism. And the different colored light is only three types, red, green and blue.

The most important proof is why green light is not appear at the first when white light dispersed by the prism and green light is appeared in the middle.
If there is only one line of white light through a prism, green light sure will
appear at the first when dispersed by prism. Green light is not appear at the first because it is overlap with blue and red to form white light this time.

View attachment 6901

If the assumption of visible light only has red light, green light and blue light is correct, it also can explan why sky is blue not violet.
I found a answer claimed that sky is blue not violet is "Violet is shorter wavelength than blue and is scattered more strongly.
The sky is not violet because sunlight is weaker in violet compared to blue and the eye is less sensitive to it."
This is not a convincing answer, I believe the eyes is not less sensitvie to violet, the eye is no problem to identify violet in daily life.
And the last color in visible light is blue light is more convincing.

And there is one more prove in below photo. It also can apply my assumption.

View attachment 6902

 

How about responding to the explanations you have been given, for why you are mistaken?

 

All mammals are colorblind (dichromatic), except for a number of primate species.

 

Light does not have color, light has wavelengths. The receptors in our eyes respond to different wavelengths which our brain interprets as "color". Most human's eyes respond to three different wavelengths. Colorblind people (usually) only have 2 color receptors.

 

They have three, but one is not working properly.

 

He doesn't really seem interested in any input, he just wants to put out his idea even though it is fundementally flawed.:shrug:

 

Paul Leung:

You seem to be mixing the three additive primary colors to get a computer "spectrum".

http://www.webexhibits.org/causesofcolor/1BC.html

 

Newton's spectrum has a more natural relationship with the emission spectrum.

How would you explain the yellow atomic sodium D-line emission if you had to use red and green?

http://en.wikipedia.org/wiki/Sodium

 

No, it has all colors in the light, from violet to red.

No, green light does not appear first because it is not the longest or shortest wavelength of light. The color we see as violet is the shortest wavelength, and the color we see as red is the longest wavelength. Green is in between.

The eye is less sensitive to violet. Just because you can see it doesn't mean you are just as sensitive to violet as you are to other colors.

Also keep in mind there are two kinds of purple - spectrally pure violet (short wavelengths) and mixed red and blue (short and long wavelengths.) We see these as the same color because of the limitations of our eye. They are not the same spectrally.

 

Using the 1931 CIE data on the color response of the eye to pure spectral light and the spectrum of "Standard Illuminant D65", and the cannonical definition of sRGB used by most browsers, I have made a first attempt at a color-accurate spectrum, adjusted with a background grey to as to best capture the spectral light in the limited gamut of sRGB color reproduction.

View attachment 6904

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I don't know what is computer "spectrum", I found that newton stated that red combine with green to produce yellow
, green combine with blue to produce cyan, red combine with blue to produce magenta in Newton Color Circle.
below is link
hyperphysics.phy-astr.gsu.edu/hbase/vision/newtcol.html#c2

I found that newton have made a experiment that to overlap additive color to form other color by overlapping the opposite ends of two spectra
homodiscens.com/home/ways/perspicax/color_vision_sub/art_color_theory

 

So what. Did you read the posts that responded to your OP? Color is simply how our brains process the interactions of the electric field of photons with a specific energy and the cones (photo receptors) in our eyes.

 

I think you have a bit misunderstand, I mean why green is so late to see after light through a prism.

View attachment 6910

 

It seems that english is not your first language so part of the problem may be that.

The deviation angle of the light rays leaving the prism is a function of the wavelength. The different colors we see are due to the different waveleghts (or energy) of the light waves.

Look at this.