What is the total number of colors that can be perceived by human vision?
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This question is a topic of current research—several groups are measuring how fine a difference between two colors can be perceived. This type of measurement will ultimately help us determine how many colors the "average" human can perceive. The research is part of a larger field called psychophysics.\n\nColors are first detected by individual cones in the retina. These cones contain various opsin pigments, which absorb only red, green, or blue light, depending on the pigment's absorption spectrum. The information about what colors have been absorbed is sent to the visual cerebral cortex of the brain. Quite a bit of integration and processing of this signal occurs before it reaches its ultimate destination.\n\nIt is now believed that humans can perceive on the order of millions of colors. Most estimates are around 10 million. This makes sense when we consider, for example, computer monitors: We notice a difference when we switch from "thousands" to "millions" of colors. Millions in this case corresponds to 224—or 16,777,216—colors for a 24-bit display. Of course, this simple test only tells us that we can see more than "thousands" of colors, but it doesn't give us an upper limit. According to Kandel et al. (reference below), "The superiority of color perception over brightness perception is evident in the fact that we can discriminate only 500 gradations of brightness but we can discriminate more than 7 million gradations of color."\n\nBecause people vary in the overall number of cones they have and the number of each cone type, they vary in the number of colors they perceive and in what color is perceived given a particular input color at the retina.
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0 is the additive identity.\n1 is the multiplicative identity.\n2 is the only even prime.\n3 is the number of spatial dimensions we live in.\n4 is the smallest number of colors sufficient to color all planar maps.\n5 is the number of Platonic solids.\n6 is the smallest perfect number.\n\nLook here for the continuation:\n\nhttp://www.gotfacts.com/numbers1.php
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Actually a rainbow contains the entire visible light spectrum. Our words and terms for individual colors is (somewhat) arbitrary.\n\nThere is nothing inherent in physics of color or our eyes why, for instance, light with a wavelength around 470 nanometers should be a distinct color (in this case blue). It seems like a strange idea, because our use of language cements the notion that these colors are somehow special when compared to light at intermediate wavelengths.\n\nTests have been done with children of different cultures to see if there is some hardwired circuitry in the human brain to identify distinct colors the same way. In other words, we see red, blue, green, but does another culture see (what we call) purple, blue-green, and yellow-orange as their primary colors?\n\nAs an aside it is interesting to note that ancient Greek and Roman texts, for instance, tend to have a lot fewer color terms than modern works of literature. \n\nAn early test in the 19th century where anthropologists did the ask-kids-color test suggested that in other cultures people tend to pick out colors from the base set of 11 in English (red, yellow, green, blue, brown, purple, pink, orange, black, white, and grey) - suggesting that there is something to the idea that these colors are hardwired into the brain.\n\nOn the other hand, at least one more recent study found the opposite - that when shown a selection of hues children from another culture did not pick out the 11 English terms as special or primary.\n\n(Later of course the system gets refined, as physics lets us know how to combine colors in different situations. That is, once you pick "blue" as one of your special colors, then physics demands that the other primary colors are red and yellow. But it is not unique. If you start with purple then blue-green and yellow-orange are the other primary colors.)\n\nBut, regardless of whether or not some colors are hardwired into the brain, a rainbow shows a continuous spectrum across the visible light range and beyond - extending slightly into the infrared and ultraviolet regions.\n\nSo, the reason why a rainbow has the 7 primary colors is that these are the ones which we have identified and named as being "special."
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The CD acts in a similar manner as a prism and splits the light into it's component parts.  Visible light is actually made up of several colors (The colors of the rainbow: Red, Orange, Yellow, Green, Blue, Indigo, Violet) and if the light is refracted it can split and you can see all the colors of the light spectrum.
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I suppose the answer is ultaviolet but as it is outside the visual spectrum of elctromagnetic radiation I can't see how you could define it as a coloUr.
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From a physics/physiology standpoint, we have color because light waves come in different lengths and our eyes perceive a limited band of thoses lengths with differing responses by light sensors in the eyes.\n\nFrom an evolutionary standpoint, color vision (as opposed to black and white), gives us a great deal more information to process our environment.  For instance, a brightly colored bird might hardly be visible to an animal with only black and white vision, but we see it easily, even against a confusing background.  Color can help us see the difference between animal (browns) and plants (greens), healthy(a child covered in mud) and unhealthy (a child covered in blood), and other differences that are more easily recognized due to the greater information richness available.
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RED has got the highest frequency among the seven colors and VIOLET has the least frequency.\n\nThe formula for energy is \nEnergy = h * v  ( where v is a greek alphabet pronounced as 'nu'.I couldnt type that in my keyboard. Nu represents the frequency. h is the plank's constant)\n\nThus energy is maximum for the RED color. When energy is maximum it has the capacity to travel long distances and thus we are able to see it even for a distance.\n\nHope so u got what u wanted.
199624
mostly black, i.e. over 67%. then the blue and green. am not considering the others as cat eye, etc.
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Wow, what a prick...he probably knows less science than you do. He's definitely further off from the truth!\n\nColors as we see them are nothing more than photons. Which is electromagnetic radiation. We perceive different wavelengths (or frequencies) as different colors. So in a way colors do have a frequency associated with them. Blind people cannot recognize these though. The only way humans can recognize electromagnetic radiation (in the visible zone) is by seeing. By definition a blind person can't do that.\n\n(Well, technically we can also feel photons if lots of them hit us...as heat. But we cannot differentiate different frequencies, and the intensity of the light has to very extreme, like sunlight).
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blue... just look at the sky w/c is so vast and also to the bodies of water. another color... hmmm.... is black, most of our day is night, right?
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droplets of water in the air refract light and break it into the visible specturm. thats way you see the different colors.
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Our reaction to color is almost instantaneous and has a profound impact on the choices we make everyday. Below is a quick look at general responses to colors based on research, historical significance of color and word association studies. Different cultures react to colors differently and this brief overview focuses on the responses of people in the Western Hemisphere. \n\nRed has more personal associations than any other color. Recognized as a stimulant red is inherently exciting and the amount of red is directly related to the level of energy perceived. Red draws attention and a keen use of red as an accent can immediately focus attention on a particular element. \n\nOrange, a close relative of red, sparks more controversy than any other hue. There is usually strong positive or negative association to orange and true orange generally elicits a stronger “love it” or “hate it” response than other colors. Fun and flamboyant orange radiates warmth and energy. Interestingly, some of the tones of orange such as terra cotta, peach or rust have very broad appeal. \n\nYellow shines with optimism, enlightenment, and happiness. Shades of golden yellow carry the promise of a positive future. Yellow will advance from surrounding colors and instill optimism and energy as well as spark creative thoughts. \n\nGreen occupies more space in the spectrum visible to the human eye and is second only to blue as a favorite color. Green is the pervasive color in the natural world that is an ideal backdrop in interior design because we are so used to seeing it everywhere. The natural greens, from forest to lime, are seen as tranquil and refreshing, with a natural balance of cool and warm (blue and yellow) undertones. Green is considered the color of peace and ecology. However, there is an “institutional” side to green, associated with illness or Government-issued that conjure up negative emotions as do the “slimy” or bilious greens. \n\nBlue is the overwhelming “favorite color.” Blue is seen as trustworthy, dependable and committed. The color of sky and the ocean, blue is perceived as a constant in our lives. As the collective color of the spirit, it invokes rest and can cause the body to produce chemicals that are calming; however not all blues are serene and sedate. Electric or brilliant blues become dynamic and dramatic, an engaging color that expresses exhilaration. Some shades or the overuse of blue may come across as cold or uncaring. Blue is the least “gender specific” color, having equal appeal to both men and women. \n\nPurple embodies the balance of red simulation and blue calm. This dichotomy can cause unrest or uneasiness unless the undertone is clearly defined at which point the purple takes on the characteristics of its undertone. A sense of mystic and royal qualities, purple is a color often well liked by very creative or eccentric types and is the favorite color of adolescent girls. \n\nBrown says stability, reliability, and approachability. It is the color of our earth and is associated with all things natural or organic. \n\nGray is timeless, practical, and solid. A longstanding favorite suit color, gray can mix well with any color. Although well like and often worn, people rarely name gray as a favorite color possibly because Gray also is associated with loss or depression. \n\nBlack is authoritative and powerful; because black can evoke strong emotions too much can be overwhelming. A classic color for clothing possibly because it makes the wearer appear thinner and more sophisticated. \n\nWhite projects purity, cleanliness, and neutrality. Doctors don white coats, brides traditionally were white gowns and a white picket fence surrounds a safe and happy home.\n\nSome of the studies done in the past such as the one mentioned about pink being the best color for prison cells have been in more recent studies proven not to hold up.  At one point people who were dieting were encouraged to buy blue light bulbs to
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Great question!\n\nThe human eye and the real world have a range of light and dark values from 100,000 to 1.\n\nMedia like film and digital cameras have traditionally only been able to capture or show about 500 to 1 in ranges.\n\nThe next generation of digital cameras will compete on pixel quality and range sensitivity, not just megapixels.\n\nSee the cool links below:
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RED (Even if it can reflect all the colors, you are not sending them to the object)
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no i don't have any info. but i think we're able to detect all of the colors of the spectrum.
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We don't know that your subjective experience of the color green is the same thing as my subjective experience, anymore than we can know if your experience of the taste salty is the same as mine.  What we can know is that, if we were to show pictures of the same object to a number of people, and asked them to identify its color, there would  be a great deal of agreement in the answers.  But it would not be 100%, because one person might consider a color between red and orange to be red, another would call it orange.  It's interesting to me, as someone who is red-green colorblind, to see people, usually ones with normal color vision, insist that there are rigid definitions of colors.  Like, they will insist that the colors of the rainbow are, precisely, red-orange-yellow-green-blue-indigo-violet. (Roy-G-Biv, the physical science teachers call it.)\nIn fact, the potential frequencies of visible light, in other words the colors of the light, vary continuously from just above infrared to just below ultraviolet; there is no hard and fast definition of "yellow". And different cultures divide up that spectrum differently.\n\nGetting back to your question, I suppose scientists could do experiments with the chemical receptors that detect color in light.  People with normal color vision have three different kind of receptors, which are sensitive to three different colors of light.  (I only have two kinds of color receptors.)  It is the levels of excitation of each type of receptor that determines what color is being perceived.  That is why we can model any given color by mixing together just three colors, as in a TV set.  Scientist could probably determine if chemically these receptors were the same in various individuals; for all I know that research may have already been done.
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Red = 625 to 760 nm\nOrange = 585 to 620 nm\nYellow = 565 to 590 nm\nGreen = 520 to 570 nm\nBlue = 440 to 490 nm\nIndigo = 420 to 440 nm\nViolet = 380 to 420 nm\n\nThese are approximate wavelengths for the visible spectrum in nanometers (notice how some values overlap). Taken from Wikipedia.