We have 3 types of cones in our eyes: red, green and blue. How do we perceive the color violet?
477940
Haven't you noticed that violet seems dim compared to blue? That's because only the blue cones are reporting it, but the green cones report a little when blue light hit them.
398924
Interesting question. Our humans eyes only see blue, but in fact there is a myriad of colors in the sky projected by the sun's rays. I think the other colors are in the ultraviolet spectrum, but I'm not entirely sure
276633
No. \nHumans see the color purple as stimulation of red AND blue receptor (Purple is not a primary color). \nAnyway, whatever colorblindness you have, it never would affect only one color, because the ratio of the excitation of two or more different types of photoreceptors contributes to most colors (You have only three different kinds of color receptors, but you can see millions of colors). \nSo deficiency in one photoreceptor type affects not only its primary color but many others too. \n\nA nice webpage for a simulation of how color blind people see colors are \nhttp://www.vischeck.com/\nhttp://jfly.iam.u-tokyo.ac.jp/html/color_blind/text.html#see
29546
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."
448202
If you shine a white light through a prism, the light is refracted and you get a rainbow. Thats how you can see the different wavelengths in white light.
728342
Different animals see different ranges of color.  Scientists can determine this largely by looking at the structure of the eye, to understand what light waves a structure responds to.
1154676
It has to do with the light sensitivity of the different types of light receptor cells in the eye. There are two types. The cones which see brightness and color are concentrated at the center of the retina. The Rods which are sensitive to low light and contrast (shades of gray) are concentrated at the edges of the retina. By concentrating on your peripheral sight you can just make out the fainter objects in the sky. This is what is called seeing out of the corner of your eye.
1002169
All the colours we humans see is a combination of the 7 colours spectrum of visible light that we know as VIBGYOR( Violet, Indigo, Blue, Green, Yellow, Orange and Red). Any object that we see gets its colour from the light rays that are reflected by that object if all the rays are absorbed by an object it looks black and if all the colours are reflected back it looks white. Due to scattering effect of the atmosphere the blue spectrum of light is reflected and hence it looks blue. The grass reflects back the green spectrum of light hence it looks green.
1184007
The colored part of your eye is the iris, and all it does is control the amount of light that passes into the eye by varying the size of your pupil.  Light passes through that opening to the retina at the back of the eye where the rods and cones convert the lightwaves into the nerve signals that your brain recognizes as objects, colors, etc.
793828
We see things in different colours because light (usually white) reflects off surfaces and reach our eyes with a different frequency, for some is absorbed. When NO light reach our eyes, it simply appears as black. You can see this as some form of 'natural default' (i coined this term myself). \n\nTo help your understanding, think of seeing a piece of paper filled with different patches of colours and holes, placed in front of vaccuum space. The black that you see will be the holes where no light get bounced off. \n\nHope this helps=)
1049262
Any substance appears coloured because it absorbs all other wavelengths of the visible spectrum other than the wavelength of its colour.i.e if a substance is blue in colour then it absorbs all other wavelenths of the visible spectrum  including red,orange yellow, green  except those pertaining to the blue region of the spectrum. Hence when these wavelenths strike the retina of the eye ,we perceive it as a blue coloured substance.\n   Now though it absorbs all other wavelenths ,it absorbs maximally those of  a coloured region complementary to its physical colour.Thus for blue the complementary colour is orange(oppt ends of the spectrum),for violet  eg KMnO4 it is red etc.So if you have to study the absorption power of a blue solution you have to use  an orange filter in the colorimeter and for an orange coloured solution eg K2Cr2O7  you will use a blue filter.
802403
You mean green colour of your eyes? Because its sexy.\n\nOr you mean green colour of objects you see? Well, I don't think it is specifically green, that is good for eyesight. Blue colour may be worse, since in the foveola centralis ("center of your exesight") there are red and green cones, blue cones are outside (RBG - just like colour tv, remember?).
166949
They all reflect all colors of the spectrum equally (red, green, blue...) which our eyes interpret as white.
347572
Actually, the reason for this is known.  There are two major types of light-sensing cells in your retina, called rods and cones.  Cones are specialized for color vision and detail-they are concentrated in the central portion of your vision, so that when you look directly at something which isnt moving, you can see it very clearly, in color and detail.  The rods are black and white, and are specialized for low-light detection of movement.  Since the cones are in the center of your vision, there are more rods in the periphery of your vision.  If you think about it, this makes perfect evolutionary sense, since you want to quickly detect things moving in your periphery, so you can react to an attack-because humans have such excellent detail vision, we can detect things in our center of vision even when they arent moving (many carnivores, such as dogs, hve a difficult time seeing stationary objects), so we dont need such good "movement" vision in the center.  This arrangement also explains why color disappeas in low light, because cones require bright light, while rods work in dim light.  In addition, this explains why, in a dark room, you can actually see better in your peripheral vision-because the concentration of cones in the center of your retina is pretty useless in low light.
398354
There's a peak absorbance of rods and cones in the retina.  Humans have three peaks which represent the primary colors (for light) red, green, and blue.  The colors we see are our brain's interpretation of input on those three colors plus general light level input from rods.  Based on the numbers of rods and cones and the absorbance spectra of the different cones, researches can get an idea of the color vision of different animals.\n\nMost mammals are dichromatic (two colors).  Note how non-colorful they tend to be.  Certain primates are trichromatic (three colors).  Birds, reptiles, amphibians, and insects are also trichromatic or more.  Note how colorful they tend to be.
195210
we see color with rods not with cones. so missing rods will not affect your color vision.\nHumans have 3 different types of cone cells, red, blue and green. The difference between the 3 types is the pigment which absorbs the light. \nIf somebody is colorblind, it can be, because the cell is there, but not the pigment, or it can be that one cell type is entirely missing. \nAlso somebody can have all three visual pigments, but less of one type, so they are not as sensitive for that color than other people are. Look at this link how colorblind people see colors.
1004080
1. white\n2. blue\n3. red\n\n...but they're all pretty sweet