If you believe Red is Red and someone else believes Red is Green, who's right?

We both could be. One of us could have some form of color blindness where improperly functioning color receptors distort, change, fade, or obliterate colors as others see them.

If I believe red is red, it would be because of what I was taught WAS the color red, and this practice had been going on for hundreds of years, with Red being REd.

So, if I am wrong in believing Red is Red when it is actually Green, then all those who believed it was Red for years, are also wrong.

In the case of the other person, he would have been told wrongly, about the color Red being Green, since everyone else would know Red is Red, and had been this way for years.

As for how we know it is true....it is RED because someone called it that in the beginning.. They could have called it Bozo or ponpalito, or whatever, and that then would have been Red.

Just like we call a car a car, why do we? Because, someone named it that. Just like we now call this web site Yahoo Answers, because that is what it is named.

So Red is Red, because someone named it that.

Analyze the terms more thoroughly. What wavelength are the photons reflecting off the surface? 620–740 nm wavelength? Then how the normal human eye/brain responds to those wavelengths is what we apply the concept "Red" to represent. 520–570 nm? Then the concept we use is "Green." But if there is a cross-wiring in the area of those light signal sensing cells, certain wavelengths can active a cell for a different wavelength abnormally. In which case, a distinction should be made between the photon wavelength and the cell being activated. How that cell activating feels at a different wavelength is an interesting question, because most of it is by association with things that are that color. It's unintuitive to consider, but if blood and everything we associate with red, everything that activated red cells instead activated the cells for green throughout our life, wouldn't green have the same feeling as red does to us currently?

"Your right, that's what we were taught, but how do we know that it's really true?"

The term "true" refers to the accuracy of the statement. How do we develop accuracy that wavelengths indicate how the eye/brain interpret the light when it comes to "colors"? Well that's simple enough, start with independent sources, get together a bunch of people and show them different wavelengths. Normality in the results would also help to reduce many potential confounding factors in the involved sense organs and brain. To further reduce such factors, we could build/use things that can measure wavelengths other than eye organs.

I would know I'm correct and would suspect that the other person has protanopia (Red-Green color blindness).

However, people with protanopia usually know that they have color-blindness because they spend their entire lives hearing people use different words, "Red" and "Green," to refer to what they perceive to be the same color, so they never assert that something is definitely Red or definitely Green. A perfectly normal conversation may go like this.

"Could you hand me the Green towel?"

"What Green towel? Do you mean the Red towel?"

"Yes, I mean the Red towel. It looks Green to me because I'm colorblind."

"Hang on, how do you tell what color a traffic light is?"

"Oh, that's easy. The Red one is always on top."

Well it's not the green one that's for sure lol..

But i know what you mean..

You should have asked it like this:

If two people looked at a colour and saw it differently, one sees red and the other sees green, who would be right?..

Neither.

"Beliefs" are worthless. Colors, however, are not subjective; we long ago made standards for them so that we could remove subjectivity in things like digital displays, TVs, print media, etc.

So the only way to tell if what you "see" as red IS red is to compare what you think is red to a "standard red" (color temperature around 1400K). If when presented with that standard source, you say you see "Red," then you're right. If you say "green," you're wrong. But to do that you have to deal in facts and evidence and tests, not just "belief."

:)

Those are the names of the colors though. Even if someone said that red is green he will still know what the color looks like. The name of the color doesn't change that. It's impossible to describe what a color looks like so if a person is color blind they will never know.

I'm classed as totally colour blind. I don't see in black and white but only see in few colours. Hard to explain because you get taught what colour things are but moat look the same.

Both for if he see Red as green then he is Red/green color blind. I am and I have to guess sometimes that is for sure.

Same hardware, same color perceptions -- usually.

I would be right, and the other person would be color blind to red and green, that's all.