Question about the colour each of us sees

[Chris_25]

This conversation came up in my sunday school class a few years ago and I could never answer it.

 

So everyone around us sees "blue", or "red", or "green"...

 

But are those colours the same for everyone?

 

If I see 'blue' is it someone else's 'green'? And vice versa?

[iNow]

Hi Chris,

 

We all detect the same frequency of light coming into our eyes and hitting the retina and activating our photoreceptors. The "color" is dependent on frequency, and that is always the same.

 

What changes is how we interpret that frequency of light. It starts in the eye itself (what concentration of cone receptors to we have), how they fire and what signal they send down the optic nerve, then it hits the brain and starts a whole new cascade of recognition effects. The first filter is the primary visual cortex, which then sorts the signal it's received from the retina and sends it along to secondary and tertiary visual processing areas, then further into other subprocessing areas (the primary visual cortex is divided into 6 functionally distinct areas).

 

It is when the signal gets to those secondary and tertiary processing areas that things shift a bit. The wiki articles on the visual system and visual cortex (linked above) are pretty good:

 

http://en.wikipedia.org/wiki/Visual_system

 

 

However, all of that is just background to setup my main point.

 

We all perceive the same frequencies of light, but we will process and interpret them differently. From having a different type or concentration of cone receptors, to slightly different wiring in the optic nerve or visual cortex, my blue may be deeper than your blue, or your red may be more orange than my red.... that sort of thing.

 

We are seeing the same frequency of light. As we grew up communicating with others, we learned to call "that fequency of light" by a certain color ("that's blue" or "that's red"), but the frequency of the light remains the same. The only difference is how we interpret it or how we perceive it, but it's important to note that the frequency coming into our visual system remains the same for all observers.

 

 

Now, where things get really tricky is when you start talking about color blindness. Basically, the person is still perceiving the same frequency of light, but have an inability to perceive differences that most others are able to see... And, in that case, someone else's green may not be your green... It could instead be brown. Wild stuff... but the frequency of the light is associated with a definite part of the electromagnetic spectrum, it's just that our unique bodies and brains do different things when perceiving and interpreting that spectrum.

 

 

Too much info? Too little? More confusing than helpful? Let us know, we'll figure it out together.

[Mokele]

We are seeing the same frequency of light. As we grew up communicating with others, we learned to call "that fequency of light" by a certain color ("that's blue" or "that's red"), but the frequency of the light remains the same.

 

Are we? Opsins can vary between individuals, and it's possible that my red is not the same as your red by just a bit.

 

Remember, we don't learn color names from anything absolute - our parents point to a blue ball and say "blue", so we call it blue. Imagine someone with a hypothetical mutation that causes them to shift the color wheel one value (red is orange, orange is yellow, yellow is green, green is blue, etc.). Because they can still distinguish the colors, they'll just give each the "wrong" label as they learn, and such an individual would call a ball blue just as I do, even though what they actually see, what they have labeled as 'blue' is different from what I see and what I've labeled as 'blue'.

[Klaynos]

Are we? Opsins can vary between individuals, and it's possible that my red is not the same as your red by just a bit.

 

Remember, we don't learn color names from anything absolute - our parents point to a blue ball and say "blue", so we call it blue. Imagine someone with a hypothetical mutation that causes them to shift the color wheel one value (red is orange, orange is yellow, yellow is green, green is blue, etc.). Because they can still distinguish the colors, they'll just give each the "wrong" label as they learn, and such an individual would call a ball blue just as I do, even though what they actually see, what they have labeled as 'blue' is different from what I see and what I've labeled as 'blue'.

 

That would not alter the frequency of the light though, mearly our detectors would be slightly skewed. From what I understand of it, that would result in a reduced spectral band being "visible" and there being less difference between the colours.

 

IMO this question is not answerable because we cannot experiance what another individual experiances.

[Mr Skeptic]

Are we? Opsins can vary between individuals, and it's possible that my red is not the same as your red by just a bit.

 

This is also why there are RGB adjustments on a screen, right? However, I've never had to use them nor know any who have. Kind of odd.

 

Remember, we don't learn color names from anything absolute - our parents point to a blue ball and say "blue", so we call it blue. Imagine someone with a hypothetical mutation that causes them to shift the color wheel one value (red is orange, orange is yellow, yellow is green, green is blue, etc.). Because they can still distinguish the colors, they'll just give each the "wrong" label as they learn, and such an individual would call a ball blue just as I do, even though what they actually see, what they have labeled as 'blue' is different from what I see and what I've labeled as 'blue'.

 

I don't think that is how it works. Are there brain portions dedicated to specific colors and hardwired to the eyes? I know some colors seems to have instinctive effects associated with them, but the mind is quite adaptable so even if the color cones were shifted like that the brain might work it out.

 

---

Most know about normal vision (with three color cone cell types) and colorblind (less than three), but not too many know of tetrachromats.

http://en.wikipedia.org/wiki/Tetrachromacy

[iNow]

Are there brain portions dedicated to specific colors and hardwired to the eyes?

No.

 

 

 

Also, Mokele - I think you and I were basically saying the same thing.

[npts2020]

I have failed every one of those "find the number in the bubbles" tests I have ever taken (at least half a dozen that I can remember). I seem to see the wrong number or none at all about 75%-90% of the time (unless I stare at them for a long time but then I am not identifying the number by color), yet I can match colors for touch-up painting. I have never been able to figure out the difference between what I see and what a normally visioned person sees since it never seems to make much difference, just that the bubble tests say that it is different. The pictures of what a normal person sees and different forms of color-blind people are a good case in point. The one of a normal person's idea of a rainbow looks, well, normal, the other pictures are oddly colored.

[Sisyphus]

This one belongs in the FAUQ (frequently asked unanswerable questions). I remember being very annoyed, myself, when my kindergarten teacher couldn't give me a satisfactory answer. (Of course, I'm sure I was articulating the question very poorly, as well.)

[GDG]

This sounds like the "qualia" problem that plagues researchers studying consciousness. One can determine experimentally how the eye responds to light of different frequencies (colors), so you could in theory determine whether or not somebody else's eyes react to light the same way that yours do. You could do experiments, and probably find out that most people agree as to what frequencies are considered "blue", which are considered "red", etc. However, there are some cultures that divide up colors somewhat differently. I understand that Russians consider "blue" and "dark blue" to be distinct and different colors.

 

The conscious experiences you have from that (called "qualia"), however, can't really be determined at this point (possibly never). So, if you and I look at the same patch of color, we might agree that the color is blue, but there is no way for you to know how "blue" looks to me. You would need to get access to my conscious experience without going through your sensory system -- essentially telepathy.

[Sisyphus]

Actually, I happened to read the Wikipedia article on primary colors today, and it occurs to me that it would interest anyone who has wondered about this topic.