# Colorblind question
**URL:** https://boards.straightdope.com/t/colorblind-question/472216
**Category:** Factual Questions
**Created:** [November 11, 2008, 6:05pm UTC](https://boards.straightdope.com/t/colorblind-question/472216 "2008-11-11T18:05:46Z")
**Posts on this page:** 20
**Page:** 2
### Author:  [@The\_Tao\_s\_Revenge](https://boards.straightdope.com/u/The_Tao_s_Revenge)
#### Post date: [November 13, 2008, 7:56pm UTC](https://boards.straightdope.com/t/colorblind-question/472216/21 "2008-11-13T19:56:13Z")
Thanks 🙂 I thought maybe there was some positional figuring. Why don’t they put words or symbols that the color blind could recognize easily as well?
(like making the red light a hexagon, the green light square and the yellow light triangle)
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### Author:  [@Punoqllads](https://boards.straightdope.com/u/Punoqllads)
#### Post date: [November 13, 2008, 9:04pm UTC](https://boards.straightdope.com/t/colorblind-question/472216/22 "2008-11-13T21:04:11Z")
> [@The\_Tao\_s\_Revenge](#):
>
> 10% sounds like alot, and red and green are important colors to know when driving. How do they tell if the stoplight says to stop or go?
From what I understand, the green on a traffic light has some blue in it. This would explain why **SkipMagic** perceives them as white.
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### Author:  [@Santo\_Rugger](https://boards.straightdope.com/u/Santo_Rugger)
#### Post date: [November 13, 2008, 9:23pm UTC](https://boards.straightdope.com/t/colorblind-question/472216/23 "2008-11-13T21:23:20Z")
> [@404 Clue Not Found](#):
>
> Are there any videos or simple 3D games that demonstrate what the world would look like to a colorblind person?
I [can think](http://en.wikipedia.org/wiki/The_Wizard_of_Oz_(1939_film)) of [a couple.](http://en.wikipedia.org/wiki/It%27s_a_Wonderful_Life)
But, seriously, there’s a [classification chart on the Wiki page](http://en.wikipedia.org/wiki/Color_blindness#Classification_of_color_deficiencies).
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### Author:  [@mnemosyne](https://boards.straightdope.com/u/mnemosyne)
#### Post date: [November 13, 2008, 9:31pm UTC](https://boards.straightdope.com/t/colorblind-question/472216/24 "2008-11-13T21:31:58Z")
> [@The\_Tao\_s\_Revenge](#):
>
> Thanks 🙂 I thought maybe there was some positional figuring. Why don’t they put words or symbols that the color blind could recognize easily as well?
>
> (like making the red light a hexagon, the green light square and the yellow light triangle)
In some places, they do! In much of Québec, the lights are horizontal, with two red squares on either end, a yellow “diamond” in the middle, next to a green circle also in the middle. There is still the problem of arrows, though, but since there are no left turn arrows (flashing green is the left turn priority), the only arrow typically seen is a right-hand one, and often it doesn’t go red, but rather simply turns off when you can’t turn legally. Right-on-red is illegal in Montreal, but relatively recent elsewhere, so a lot of intersections are still simply controlled by green arrows in the light cycle.
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### Author:  [@Terminus\_Est](https://boards.straightdope.com/u/Terminus_Est)
#### Post date: [November 13, 2008, 11:03pm UTC](https://boards.straightdope.com/t/colorblind-question/472216/25 "2008-11-13T23:03:02Z")
Here’s a site - [Vischeck](http://www.vischeck.com/vischeck/vischeckImage.php) - that allows you to upload an image to see what they would like to a color blind person. You can choose between three different types of color blindness. You can also look at some [examples](http://www.vischeck.com/examples/).
Here’s a link to BoardGameGeek with [plenty of images](http://www.boardgamegeek.com/geeklist/20738), showing how different games look. Some games do well, some don’t.
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### Author:  [@Cider\_Depot](https://boards.straightdope.com/u/Cider_Depot)
#### Post date: [November 14, 2008, 12:19am UTC](https://boards.straightdope.com/t/colorblind-question/472216/26 "2008-11-14T00:19:19Z")
> [@Racer1](#):
>
> I’m the same as this. The only time I’ve ever had problems is with one level on Doom years ago. I couldn’t make out my character against the background.
>
> Being colour blind is hard to explain. People assume you see in black and white or can’t see a particular colour at all. It’s not like that, it comes in levels.
I hear that. I get so sick of hearing questions like “What color do you see instead?”
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### Author:  [@Hypnagogic\_Jerk](https://boards.straightdope.com/u/Hypnagogic_Jerk)
#### Post date: [November 14, 2008, 12:23am UTC](https://boards.straightdope.com/t/colorblind-question/472216/27 "2008-11-14T00:23:36Z")
> [@mnemosyne](#):
>
> There is still the problem of arrows, though, but since there are no left turn arrows
Maybe in Montreal, but I see left turn arrows quite frequently. (I think I’ve even seen an intersection with a green, yellow and red left turn arrow, which could certainly be confusing to a colourblind person.)
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### Author:  [@GuanoLad](https://boards.straightdope.com/u/GuanoLad)
#### Post date: [November 14, 2008, 1:26am UTC](https://boards.straightdope.com/t/colorblind-question/472216/28 "2008-11-14T01:26:13Z")
I have red-green colourblindness, which as an artist is something of a minor inconvenience.
It manifests mainly in certain neutral shades of either red or green being indistinguishable from each other, so that I may not see subtleties, like pale pink, or in dim light I may not pick what is usually a dull red from a dull green.
[In this example](http://www.guanolad.com/stuff/redgreen.gif), if something was either one of these shades, I wouldn’t be able to tell you if it is reddish or greenish.
Also, fleshtones have a lot of red, but they also have a hint of green. I can’t pick those up at a suitable enough level to re-create it accurately in my artwork.
And nobody should employ me as an interior design colour coordinator.
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### Author:  [@mnemosyne](https://boards.straightdope.com/u/mnemosyne)
#### Post date: [November 14, 2008, 2:14am UTC](https://boards.straightdope.com/t/colorblind-question/472216/29 "2008-11-14T02:14:53Z")
> [@Hypnagogic\_Jerk](#):
>
> Maybe in Montreal, but I see left turn arrows quite frequently. (I think I’ve even seen an intersection with a green, yellow and red left turn arrow, which could certainly be confusing to a colourblind person.)
Actually, in a lot of Montreal, the traffic lights are the round vertical red-yellow-green/flashing green configuration, which actually isn’t very colour-blind friendly at all!
I was thinking of Sherbrooke when I wrote that post. I do seem to recall that Sherbrooke makes good use of the arrows for everything, though. I’m sure there are some with tri-colour arrows (I’m thinking Léger and Blvd Bourque, maybe, coming from Léger? Probably the whole area around the Carrefour), but the basic configuration is the horizontal one at pretty much every intersection. I’ll pay more attention when I go down tomorrow or Saturday to visit family.
Sherbrooke is a special place. When right-on-red became legal, instead of allowing right-on-red, they simply put right-turn arrows in and signs restricting ROR turns _everywhere_.
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### Author:  [@CutterJohn](https://boards.straightdope.com/u/CutterJohn)
#### Post date: [November 14, 2008, 2:21am UTC](https://boards.straightdope.com/t/colorblind-question/472216/30 "2008-11-14T02:21:44Z")
Would a person who is red/green colorblind be able to see in a dim red light, such as is commonly used in darkrooms? Or would it just become a dim white light?
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### Author:  [@Cider\_Depot](https://boards.straightdope.com/u/Cider_Depot)
#### Post date: [November 14, 2008, 2:59am UTC](https://boards.straightdope.com/t/colorblind-question/472216/31 "2008-11-14T02:59:09Z")
> [@CutterJohn](#):
>
> Would a person who is red/green colorblind be able to see in a dim red light, such as is commonly used in darkrooms? Or would it just become a dim white light?
I used to work in a darkroom. The light is red.
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### Author:  [@Cider\_Depot](https://boards.straightdope.com/u/Cider_Depot)
#### Post date: [November 14, 2008, 3:20am UTC](https://boards.straightdope.com/t/colorblind-question/472216/32 "2008-11-14T03:20:26Z")
There seems to be a commonly held misconception that people with red/green colorblindness replace the colors with some third color. This is not the case. We simply cannot discern a _difference_ between the two. We don’t see white, or a void where other see color, or a dotted outline or anything like that. We see the colour we see, which just happens to be one colour, whereas you see two different colors.
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### Author:  [@Reply](https://boards.straightdope.com/u/Reply)
#### Post date: [November 14, 2008, 5:48am UTC](https://boards.straightdope.com/t/colorblind-question/472216/33 "2008-11-14T05:48:54Z")
Thank you, Santo and Terminus!
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### Author:  [@Moirai](https://boards.straightdope.com/u/Moirai)
#### Post date: [November 14, 2008, 2:41pm UTC](https://boards.straightdope.com/t/colorblind-question/472216/34 "2008-11-14T14:41:21Z")
Hubby is color blind, but has gotten quite good at seeing color correctly by the frequency or intensity of it. But dull colors- say, red, brown or green- would be hard unless they were next to each other.
He is phenomenally good at seeing patterns, though, like camouflaged stuff (draped tanks, etc).
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### Author:  [@pravnik](https://boards.straightdope.com/u/pravnik)
#### Post date: [November 14, 2008, 4:24pm UTC](https://boards.straightdope.com/t/colorblind-question/472216/35 "2008-11-14T16:24:21Z")
> [@Terminus\_Est](#):
>
> Here’s a site - [Vischeck](http://www.vischeck.com/vischeck/vischeckImage.php) - that allows you to upload an image to see what they would like to a color blind person. You can choose between three different types of color blindness. You can also look at some [examples](http://www.vischeck.com/examples/).
Heh. On those examples, the first two pictures of Earth look exactly the same to me. No difference whatsoever. I can distinguish between the pictures of the hats and the rainbow spectra on Santo Rugger’s Wikipedia page, but not those. Are they markedly different to you non-colorblind folks?
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### Author:  [@Punoqllads](https://boards.straightdope.com/u/Punoqllads)
#### Post date: [November 14, 2008, 6:16pm UTC](https://boards.straightdope.com/t/colorblind-question/472216/36 "2008-11-14T18:16:52Z")
> [@pravnik](#):
>
> Are they markedly different to you non-colorblind folks?
Very. The leftmost has areas of high saturation green, where the equivalent areas in the center picture are a muddy yellow.
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### Author:  [@Terminus\_Est](https://boards.straightdope.com/u/Terminus_Est)
#### Post date: [November 14, 2008, 6:19pm UTC](https://boards.straightdope.com/t/colorblind-question/472216/37 "2008-11-14T18:19:59Z")
> [@pravnik](#):
>
> Heh. On those examples, the first two pictures of Earth look exactly the same to me. No difference whatsoever. I can distinguish between the pictures of the hats and the rainbow spectra on Santo Rugger’s Wikipedia page, but not those. Are they markedly different to you non-colorblind folks?
The are quite different. In the standard picture, the continents are green. Under deuteranopia, they’re olive-brown. Under tritanopia, they are blue - almost the same color as the ocean. The hats, incidentally, are yellow, orange, green, pink, and blue (from left to right). Under deuteranopia they are yellow, yellow-brown, brown, not-so-brown, and blue.
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### Author:  [@pravnik](https://boards.straightdope.com/u/pravnik)
#### Post date: [November 14, 2008, 6:37pm UTC](https://boards.straightdope.com/t/colorblind-question/472216/38 "2008-11-14T18:37:49Z")
Okay, I can barely, barely see that now that you guys have pointed it out. Brazil and the eastern coast of South America are green in the first picture, but sort of brownish in the second one. It’s not at all obvious, though, I have to look very carefully to see any difference, and I wouldn’t have seen it at all if you hadn’t told me.
On the hats picture, though, I can easily see a difference. The second hat from the left is reddish-orange in the first and greenish in the second. The Isihara “dots” picture…sheesh, I hate those things. They look a little different, but the number isn’t any easier to see in either one of them. I like how it says “Note that the digit (3) is practically invisible.” Yeah, I noticed that on the first one, actually.
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### Author:  [@capybara](https://boards.straightdope.com/u/capybara)
#### Post date: [November 14, 2008, 7:45pm UTC](https://boards.straightdope.com/t/colorblind-question/472216/39 "2008-11-14T19:45:29Z")
> [@pravnik](#):
>
> On the hats picture, though, I can easily see a difference. The second hat from the left is reddish-orange in the first and greenish in the second.
So the middle/third hat in the left pic isn’t bright green to you?
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### Author:  [@pravnik](https://boards.straightdope.com/u/pravnik)
#### Post date: [November 14, 2008, 8:04pm UTC](https://boards.straightdope.com/t/colorblind-question/472216/40 "2008-11-14T20:04:41Z")
> [@capybara](#):
>
> So the middle/third hat in the left pic isn’t bright green to you?
It’s green, but it doesn’t look too much different from the third/middle hat in the middle pic. The middle hat in the left pic is a lighter green, the middle hat in the middle pic is a darker or more brownish green, but they’re pretty close. The second and fourth hats are obviously different, though; orange/red and pink in the left pic, both greenish in the middle one. Is the middle hat just a little different, or very different?
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