Why is it impossible to imagine colors that you haven't seen?
345883
because your mind only bases imagination on what it has experienced.  it may put things together really weird, but it only puts out what has gone in
1153443
There is no color that can not be seen on earth. Either it exists naturally or can be created because; as has been noted many times, humans can only see within a certain spectrum range. We know the wavelengths of light and can recreated them, so no color we can see can not be seen right here on earth.
616502
In the 1950s in Europe and the United States, it suddenly became popular to debate whether people dreamed in color or only in black and white. \n\nSome contended that we dream in black and white BUT REMEMBER OUR DREAMS IN COLOR —that is, we “paint them in” afterward. What is interesting about this debate is not the question itself but rather the time that the question came to be asked. The debate was popular in the late 1950s. Prior to this time, however, in all of the literature that exists that pertains to dreams, the question of color never came up. Freud did not raise it, nor did Jung or any other psychoanalyst of the early twentieth century. \n\nIf you have never seen a black-and-white world, it would be hard to imagine one—wouldn’t it? The cause for this debate appears to be the widespread diffusion of black-and-white television in the United States and Europe in the 1950s! It is true that people can dream in black and white; for that matter, there is no reason to discredit anyone’s claim to occasionally dreams in black and white—or purple, or Technicolor, or Day-Glo. Much as our brains effortlessly recreate our outside world with all of its vivid colors. so too can they recreate the black and white world we see in films, on television and in photographs. No one hears much about the black and white theory today. Most people have color TV sets. Now the only time we might dream in black and white is after spending long weekends watching old movies on cable.
316761
There are different kinds of color blindness.  The most common is red/green.  This occurs when the chromosome that codes for how we see color is missing either the red or green gene or else there is a chimeric gene (it has both red and green on the same gene) that only allows one of the colors to be expressed. If the chromosome doesn't have both the red and green gene being properly expressed than the person will be red/green color blind.  This means that he/she will not be able to perceive red (if that is the gene missing) or green (if that is the missing gene) There are no drugs that can help this, because you are missing the gene -- there is no way to "fix" that.  Hope that helps.  :)
825101
We see impossible things just fine.\n\nIt's not that our mind can't see them, it's just that we can't comprehend them - we have no idea what it is we're seeing because we have no idea how we should be putting those images to ideas.\n\nWhen the Native Americans saw the ships Columbus was in, they would first have seen the sails, and been confused by what was going on.  When they saw that they were boats, they would have understood - "these are big boats, like the ones we use to sail around the island."  Remember, Columbus landed on the island of Hispaniola.\n\nAt any rate, whoever told you that the Indians on Hispaniola couldn't see the boats was wrong.
863959
see: http://en.wikipedia.org/wiki/Color_vision\nhttp://en.wikipedia.org/wiki/Color_blindness
785556
I think their dreams would be blank as well. How can you dream of something you have never seen? If once they saw and went blind then I would say yes they do. If they were born blind, then there is nothing for them to see even in sleep. I wouldn't think they would see colors shapes or anything due to the fact they don't know what they look like.
546324
This a question I answered once!\n\n1. Blind born people aren't able to visualize because the visual area is not developped\n2. People that blind during their life ... is possible if visual area is intact ... ask someone in this category ...
4502
There is a test where there are a bunch small circles within a larger circle. A number is written in the small circle with a different color. If you can't read the number then you are color blind. It's called the Ishihara test.
187887
I feel its the opposite. Because every object absorbs all colours in the white light and reflects only a particular colour which is seen by your eyes. Now there are many times where the eye can be fooled like the forward mails you would have seen (optical illusion ones).\n\nIf something is Blue its actually the opposite of blue, that is, all other colours mixed but blue ;) \n\nIf something looks black, its merely not capable of reflection, so you dont know what its colour is...\n\nhehehehehehe wierd theory right?
236509
Because of peoples perception of shadows is all about the unknown and the dark. So, in the absence of color it's always a shade or two from darkness. You wouldn't be scared so easily in a lighted area as you would if that same area was nearly or completely dark.
689330
This sounds like synesthesia. Most of the times I've heard of this it ties colors to letters. A is red, q is yellow, that sort of thing, but I think the term applies to any mixing of the senses.\n\nAs neurological conditions go, this one sounds kind of fun. Enjoy!
64367
Actually there is no colore\nAnd we see it blue because of light reflex in the sky.
107065
Neither the color blue nor any other colors have  sound.Colors don't have sounds.Colors are visible,not audible. >
208190
I'm colour blind actually....I have a very hard time with shades and red-greens.  I see colour differently than you do.  Or don't see as the case may be.
771617
What we perceive as colors is a very limited experience, we only see in the narrowest of vision. Color is as we perceive it.
64730
That really is a fun and interesting question!!!\n\nOur cones are not necessarily identical, which means that out perceptible gamut will not map identically on the xy plane. (Click on the link from Discover Labs listed below for pictorial examples of these differences, for example in color blindness) \n\nHowever the difference for most of us is so insignificant that it doesn't matter. \n\nThat is what professionals like photographers, artists and cinematographers, etc. base their success in their professions on. Also remember that colors are not arbitrary but are determined by their wavelengths. There may be some other issues on a quantum level, More...\n\nYou'll find some fun, interesting and easy to understand theory in addition to great explanatory  illustrations here at this link:\n\nhttp://www.discover.uottawa.ca/~aelsawah/csi4133/Lab02.htm