how do you know if two people see the same colour - if they describe something as being blue for instance?
461513
I dont think you can. =^P It would be wierd if I was seeing blue and somebody else was seeing (my version of) red and saying it was blue... Mabye everybody has different color views. Never know.
63071
Mixture of the primary colors forms a secondary color. \nFor Example,\nGreen + Red  = Yellow\nGreen + Blue = Cyan\nRed+Blue+Green = White.
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?
54756
It's just a color.\n\n\nMaybe they are color blind
328064
Blue! Because, with the same shade, you can find passion, sadness, basically anything. The same color can fit any mood.
823019
Yes it is testable. And there are colorblind people who do not see some colors at all. Other than that there are lots of variation on how well each person can detect different variations of a color. Woman generally can detect slight changes in a color better than me. ( this is proven not a generalization). Best way to answer your question is by comparing it to singing. There are mute people who can not sing. Everyone else can sing but lots of variation in how well. Same with color recognition.
182612
As fewofmany mentioned, it's just three numbers smashed together, so you could conceivably write a function that compares them:\n\nColorX = 00FF00\nColorY = 00EE00\n\nThen, this means that ColorX has a Green component that is 255, and ColorY has a Green component that is 238. The two colors are identical in their Red and Blue components.\n\nIt's conceivable that you could then write a simple comparison check... Take the two colors' Red values & subtract them, and you'll end up with a measure of how similar their Red components are.  Do the same with Green, and you'll get a similarity measure for Green.  Finally, do the same for Blue, and you'll get a measure of the similarity of the Blue components.\n\nAdd up those "similarity" values, and you'll get some number.  In this case, the number is (0 - 0) + (255 - 238) + (0 - 0) = 17.  It seems that all you'd need to do is prevent that number from falling below a certain threshhold.\n\nI hope that makes sense...
537209
It depends on how one perceives colour. Some cultures only distinguish two colours, e.g. whitish and blackish, cool colours and warm colours. Most physicist see everything in terms of red or blue. I mean how do you define an indigo band? Where does this band start and stop? How would you divide up the rainbow?\nThe main reason for indigo is symmetry. Green is in the middle and Europeans have traditionally seen three colours on the red side, so three are assigned on the blue side.
474846
What colour will what be?\n\nLight is additive: red light plus green light will yield whitish light.  The blue object will still look blue.\n\nIf you mean that the light passes through the blue object onto the screen, all non-blue light will be filtered out, so the spot on the screen will look blue.
426871
Some people experience a phenomenon known as synaesthesia. That occurs when people perceive multiple senses in repsonse to one stimulus. For example, many synaesthetes report being able to smell the colors they see, even if there's no chemical around to cause them to smell something. It's just a quirk in their brain.\n\nI can "see" loud noises if my eyes are shut. Loud clattering and crashing sounds cause me to see a flash of white when my eyes are shut. Likewise, I perceive colors when I think of certain numbers. \n\n0 = white\n1 = black on a white field\n2 = yellow\n3 = green\n4 = light blue\n5 = red\n6 = brown\n7 = magenta\n8 = dark blue\n9 = brown
100159
The quote from the link explains how yellow is a combination of colors and when added to blue all the colors are represented and the result is white light.  This has to do with the fact that the normal human eye has only three different color receptors and many colors we see are mixtures. \n\n"White is the combination of all colors of light. In other words, the color white is seen when the red, green and blue channels all send signals to the brain. It follows that red light plus green light plus blue light produces white light. However red plus green without the blue produces yellow. By deduction, yellow light plus blue light most produce white light."
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.
1047284
There are two issues here, human physiology and semantics.  Stastically speaking, most people's eye will respond to a light stimuli in the same way as anothers, with a certain percentage of people having certain genetic deformities that cause color blindness.  The issue of semantics is that even in the presence of wide variations in response to light stimuli we agree upon certain naming conventions when referring to a common object, for example, we both look at an apple and refer to it's color as red, regardless of the exact response it causes in our visual system.
696478
Noa - Blue Touches Blue
551481
It's called synesthesia- Stimulation of one sense produces the sensation of another.\n\nI hadn't heard of colors=numbers, only music sparking color.\nOr colors =taste.  Very interesting.\n\nI remember hearing about this woman who sees colors when she plays music.  I'm guessing this is related. (see attached article- the very last one)
573544
Don't know what you are talking about but , different colors look different on different people, whether man or woman everyone has  a certain color that looks good with their skin tone or eye color.  You just have to experiment
21647
You can't, since it's knowledge based off of what we learn from our environment. It'd be the same as trying to describe, for example, a horse, to someone who has never seen a horse. With that example you might could give him a broad idea of what it looks like, but it would be impossible to get an accurate  and completely correct image without having actually experienced seeing one before. With colors, it's more absolute; you either know what a color looks like or you don't (unless you try to explain jungle green as a mix between forest green and dark green or something really confusing like that :-P)