How do we know we aren't color blind?

From:  "Brad"

how do you know if the sky isn't green and we are just color blind?

TB answered with this: 

Mankind has a label and description for everything we see, taste, touch, smell and hear. One of the other things we do is compare one thing to another. There are many shades of blue, green etc. The sky could have been called "bill". Then you would call it light bill as compared to dark bill. The origin of words to describe colors vary and is too involved to cover here.

Todd thought up this response: 

Because if you shine light through a prism, you see all the colors of light. Those colors are "real" colors. The sky is blue because the molecules in the sky reflect the blue light from passing through and the rest of the light continues down.

i know all pointed this out: 

the colors that we see are just a reflection of light. the color of light that is reflected is called blue. true that we could have named it differently but it would still be the same color right? it's sort of like "a rose is a rose by another name shall smell so sweet" by this it means that no matter what you call it it still is what it is

David K thought this was the solution: 

If the sky were green, then what color would the grass be? We can tell it is a different color than the sky! As long as you can differentiate the colors (if the different colors on a palate at the paint store all appear different to you) and you can associate a certain pigment with the word "blue", for example, then what difference does it make?

Casey did a bit of homework and came to this: 

about the color blindness question: There are actually tests that are available to find out whether or not you are color blind. (i saw them in a science text book). In the test, there is a picture with a number in the background (I can't remember what color everything is). If you are color blind, you will not be able to see the number that is in the background. You could probably go to a doctor & they might have some sort of color blindness test..........or check out this website (they have the type of test that I was talking about): here

maba27 gave us this information: 

we don't know we have the color spectrum, we know the length and intensity and such of the light waves we just call one end of the spectrum blue and the other end red in my humble opinion there is no way we can know for sure that what I call blue looks for you like what i see as green eyes r receptors, they receive the light, they translate it into electrical pulses and the brain translates those into an image, there is no way to tell or all our brains translate those images the same way, and or their interpretation is correct

rad1101 attempted an answer: 

Color is a property of light that can be measured empirically. The reason we know what a color is is by the position on the spectrum it occupies. Blue is always blue and red is always red.

Primo thought of a new idea: 

You would know if you are color blind because of the pigments in the eye. All the colors we see are combinations of Red Green or Blue. If you are color blind, its either you are missing one of those pigments or only have one. And if that happens, some colors will appear the same as other colors. (i.e.: some blue may appear red) so its basically easy to determine. it just takes time.

pavolka mumbled something like this: 

The sky is sort of green. It's cyan. So we ARE all color-blind. But it doesn't matter because as long as we all agree these challenges to the way things are are few and far between.

Sally did a little bit of research: 

I've actually thought of this before. But the way we describe things has been ingrained in us almost since birth. If you described a "light blue" to somebody, they would know what you are talking about because they've recognized it in comparison to a color that's called, say, purple. They can tell there is a difference. But now say that all of a sudden you switch eyes with the other person (completely impossible) and saw everything as they saw it, with your brain. What they called blue, you might call orange, but you would NEVER KNOW this for sure. They've seen the colors that way for their entire life. So if through their eyes, trees look purple, they would still call that color green. Every time they saw what you would call purple, they would call it green. So if we are all colorblind, we're all in it together and things still are what they are.

ColorMe added their thoughts: 

whatever we call a color it is still the same thing for example this type is black but we could call it green and it would still be the same color. does this make sense? what happens is that color is just light waves that are reflected from different surfaces they same type of waves are reflected no matter what color you say they are a high intensity wave will always be a high one it will not change to a low one.

bigjason wanted to add this: 

you don't know the colors aren't right but it doesn't matter. if you and i are both looking at the same color and we both call it blue then its blue although you could possibly see it the exact opposite color that I do but you have always known it as blue so its blue to you.

Darth Vader sent the force to us to answer this: 

The retina of your eye contains pigments that react to 3 different colors. Red, Blue, and green. Therefore Red, green, and blue are the easiest colors to see. Yellow is a mixture of red and green so it is also easily detected by the eye.
They also look nice :)

C.H.U.D. shared his thoughts with us: 

Electromagnetic measurements can be taken to verify that the light
coming from the sky falls within the wavelengths designated as the color
blue. Whether your eyes can see it or not there is a physical
difference between blue light and green light.

mario summed up the discussion with this: 

Perception is reality, blue and green are simply labels that we use to interpret what we see. The sky is "blue" because the majority of the population sees it as "what blue looks like". Because we perceive it, it is.