why do we see in colors?
451298
We have two types of receptors (light-sensitive nerve cells) in the retina of the eye.  The two types are called 'rods' and 'cones.'  The 'rods' (so-called because of their shape) respond to low-levels of light and are useful for night vision.  However, since all rods are pretty much identical, they do not distinguish between colors ... our dim-light rod vision is "black and white."\n\nThere are three types of cones (again, so called becaues of their shape).  One responds to long-wavelengths of light, what we call the "reds".  One responds to medium-wavelengths, what we call "greens".  And the third responds to short-wavelengths (the highest energy), what we call the "blues" (unless you live in Mississippi, then the "blues" is something different :-) ).  \n\nThese ranges of wavelengths for the three types of cones are not exclusive ... they overlap.  In other words, the long-wavelength cones also respond to medium wavelengths, although to a lesser extent.  Because they overlap, every object that gives off different mixtures of wavelengths affect the different cones by different amounts.  This experience is what we call color.  (Unless you live in Britain.  They don't see in colors.  They see in colours.)
297785
Because our "air" is composed mostly of nitrogen.  The nitrogen filters out the "blue" wave length of white light.
245658
Yes, from a physics perspective there are an infinite number of colors.\n\nBut from the perspective of your retina, there are a finite number that you can perceive, in the thousands as I recall.
59243
The light during the day comes from our star, the sun. The sunlight has to travel through air to get to us. The sunlight looks white, but it has many colors in it (for example, a prism or a rainbow breaks the sunlight into its colors so we can see them). \n\nSome of the blue part of the sunlight cannot go through the air without getting bounced around first by the air, and so it makes it look like the blue is coming from the air in the sky instead of the sun. That is why the sky looks blue.
131547
colours only mean you perceive things differently. if you were colour blind it may make things harder for you if you had to determine colours. otherwise, it probably has very little significance.
1152765
Totally blind from birth have no idea what colors are.  As you they dream what they know.  People that loose their sight later will dream in color because they have seen color.  It is very difficult for the seeing to understand those that do not.
245181
Colour is all about light.  The amount, quality, and colour of light can make a difference.\n\nYour clothing is reflecting light, thats how we see what colour it is, it can easily reflect to your eyes.
578312
Because you are seeing reflected light, and typically the light source in your bathroom/kitchen is white light from a bulb or from sunlight.  "Color" is perception based on the reflected wavelengths of light; surfaces absorb some wavelengths and reflect others. We see the reflected wavelengths.  When something "looks" white it is typically because it's reflecting all or almost all wavelengths of light.
589584
I have a friend who can see these orbs, or auras, arround people very well.  I have been with her as she has explored it more latley.  As far as we have been able to tell, the colors you see are specific to your sight.  Also they are specific to the person and the mood, state of mind or things the person you are observing are going through. If you want you can google "about auras" to see what some people have written about it.  I think this is something that you must explore by just observing people, use your friends, ask them what they are going through and see if that associates with their color at that time.
414008
Firstly,there are several colors of stars, red, yellow, blue and white. The reason they are different colors is because they are hot, very hot actually. All matter emits radiation, peaking at a wavelength (which can sometimes be seen as a color) which is dependent solely on the temperature of the body. This is known as Wein's law (pronounced Veen's law). Another cool thing is about blackbody radiation, which happens to all objects regardless of it's temperature. Most objects we encounter in everyday life are somewhere around room temperature. \n\nAs an object grows hotter, there is, more energy being released. As the energy level of radiation is increased, the wavelength becomes shorter and shorter. When the human eye perceives different wavelengths of visible light, we interpret it as different colors. The coolest stars are around 3,000 degrees Celsius and they are red stars. Next are the orange/yellow stars which are about 6,000 degrees Celsius. After that at 10,000 degrees Celsius, you will see a green star, and finally a blue star is around 25,000 degrees Celsius.\nReasons we see different colors are because of our eyes. Special parts of our eyes pick up on certain colors. For example, Rods, which are located in the retina your eye and are more sensitive are very unresponsive to red light. Cones are less sensitive than rods and more clustered near the center of the retina. Three types; red, blue and green make up the 7 million cones in a human eye. Being less sensitive than rods, cones require many more incident photons of the right frequency to trigger them. This is the main reason why we do not see color at night.
890591
By realeasing photons that travel at the speed of about 3*10^8meters per second and carry energy that have frequencies which are visible to the human eye (colors). the frequencies are so high and wavelengths soo low that it can only travel in a straight line. when they hit objects they are bounced back with diferent frequencies depending on the atoms capability to absorb light thus the light from the body is scattered in all directions in a straight line and that is why we see things. and that is why black is the absence of light and also when there is no light there is a shadow blackening of the enviroment by the use of light.
666143
because our eyes can only detect those three colors of light. Your computer screen works the same way. Manipulating the relative amounts of red, green, and blue light, plus light/dark levels, can create any color imaginable.
845181
i don't think they know for sure. they probably just study optic nerve to see the complexity of the nerve. lets say it was extremely complex mabye they see colors that are warm colors or cool colors only.
607436
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.
617565
The water particles,mixed in the air ( sky ), are responsible for this.The sunlight is refracted by those water molecules and thus we see the colour of the sky as blue.As you may remember,in the rainbow colours,Blue comes just after Violet and Indigo which are not that prominent as Blue. \nThus we see the sky blue.
199551
well nwhen white light goes through a prisdim, it breaks and turns into the colors of the rainbow. so when white light goes through the atmosphere, which acts like a prism, it breaks and we mostly see the blue
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.