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Color blindness

commandcenter.blogspot.com

61–70 of 165 posts

Re: Color blindness

#61

> I can drive a car and I stop when the light is red and go when the light is green. I'm also slightly colorblind and pure green light would be harder to distinguish from distance (not critical because there is also light position, but still). That's why traffic lights usually have cyan tint.

Discriminating a sole blinking-red vs. blinking-yellow light is a bit hard , but in practice I get it right.

Re: Color blindness

#62

>> Maybe I can help you understand how that impairment—and it is an impairment, however mild... This is actually a slightly controversial claim. While r/g color-blind individuals do have difficulty viewing colors, they seem to have an easier time seeing through camouflage: A study on the ability to distinguish tones of khaki: https://www.discovermagazine.com/mind/in-combat-stick-with-t... There is strong anecdotal ev…

There are some normal trichromats that also better resolve luminance and S-cone signals, so it's not necessarily mutually exclusive.

https://jov.arvojournals.org/article.aspx?articleid=2135713

Normal trichromats read Ishihara plates using their L- and M-cones. Red-green color vision defective observers rely on S-cone and luminance signals in reading the plates. Some normal trichromats can read the hidden digit plates because they can extract S-cone signal difference efficiently despite the distraction from L- and M-cones.

Re: Color blindness

#63
post #8

I'm r/g colorblind, and suddenly the indistinguishability of small colored objects makes sense now. Wow. Okay then. I hate multicolor LEDs with a passion. Those little amber or green dots look identical to me, even when you put them side by side. I use a phone app that uses the camera and shows me RGB values at a reticule. I've gone through rack and racks of equipment with that app, looking for things like dead drive…

I'm not colourblind enough to be "legally" colourblind (that is to say I don't have an accurate diagnosis) but I still feel your pain. I particularly hate status indicators that are orange/green, rather than red/green, because I just cannot tell them apart at all, where as at least the red gets a bit darker so that I can tell that "dim is off", for example. Nintendo seem to be pretty bad for this, at least with the Wii, because the LED is forever this weird yellow that looks like what I'd call yellow, but actually isn't, and I had to actually switch to the input on the TV just to check if it was switched off or if I'd managed to catch the button while dusting under the TV.

Re: Color blindness

#64
post #33
post #9

Great article. Ummm... dumb question, but... stars are colored? (Color blind poster here).

Yes. I still see the colors of stars, but it's like a pale color. They are mostly white, but some tend toward red, others yellow, others blue. There's definitely a difference. When I see Mars, it is definitely more red, especially so when it is closer. But I distinctly remember my young eyes, probably when I was 4, that the the stars had a lot more color than they do now. I remember talking about it with my mother wh…

Are you by any chance one of the (described in the article) tetrachromates?

Re: Color blindness

#65
post #27

I've got mild red-green colorblindness (less severe than the author's); this article is great, and goes into much more detail than I knew beforehand. If I could add some suggestions to the author's at the end: * First, if you have the option of using one or the other, do so. Like, you can use red, blue, yellow, purple, and black for lines on a graph before you even need to find an additional color like green. * Secon…

How about this for selecting. Colour scheme: just display a colourblind was test and ask the user to select the one they can or can't read. Then you don't have to rely on them knowing what the different types are at all.

Re: Color blindness

#66
post #8

I'm r/g colorblind, and suddenly the indistinguishability of small colored objects makes sense now. Wow. Okay then. I hate multicolor LEDs with a passion. Those little amber or green dots look identical to me, even when you put them side by side. I use a phone app that uses the camera and shows me RGB values at a reticule. I've gone through rack and racks of equipment with that app, looking for things like dead drive…

I'm also Red-green colourblind, and also use a mobile app to check RGB values of things! I also use a Windows traybar app that I wrote with Delphi about 15 years ago, which gives me a dropper I can use anywhere in the screen to see RGB values.

I've also noticed that it's much more difficult to differentiate tones and colours of small objects.

Cues were mentioned in the article, and I think I subconsciously rely on these a lot. For example, with traffic lights I know what the colours should be from top to bottom, and so I "see" them as the right colours - yet if you took photos showing only the colours in the abstract, I couldn't tell any difference between red and amber, and indeed I wouldn't be able to accurately tell you what colour any of them was.

Something people find interesting is that I often don't know what colour something is, but I'm often able to narrow it down to 2 or 3 choices - usually based on context and other cues, and also based on how I know I can misperceive colours. For example, I know I often see pink as grey, so if you showed me something pink, I might think it was "pink, or grey or green".

Another random anecdote that demonstrates the use of cues: years ago we had an old CRT TV, and every now and then it would suddenly display only in black and white. It really annoyed my wife, but I never even noticed - I guess in my head I "saw" someone's coat as red, for example. My mind just kind of filled in the blanks, like I suppose it must always do.

Re: Color blindness

#67
post #17
post #8

I'm r/g colorblind, and suddenly the indistinguishability of small colored objects makes sense now. Wow. Okay then. I hate multicolor LEDs with a passion. Those little amber or green dots look identical to me, even when you put them side by side. I use a phone app that uses the camera and shows me RGB values at a reticule. I've gone through rack and racks of equipment with that app, looking for things like dead drive…

> I use a phone app that uses the camera and shows me RGB values at a reticule. Could you share the app name? It would make my life a bit easier (I hate those red/amber/green leds that look identical) :)

I use Color Blind Pal on Android. Been using it for a few years.

If you get it, I'd recommend going into the settings and increasing the sample size - it defaults to "small", which given the way it flickers I'd guess means "1 pixel" :) I use it on the "large" setting, and it works great.

Re: Color blindness

#68
I wrote an app that aimed to simulate vision impairments, including types of colour blindness.

The idea is that the designer or developer can point their iPhone/iPad at design to get some idea of what it might be like for someone else to view it.

https://apps.apple.com/gb/app/vision-impairment-simulator/id...

Re: Color blindness

#69

Interesting thing about people with deuteranomaly, is that in some situations we can utilize luminance and S-cone data better than most people with normal vision. That's how Ishihara hidden plates work (numbers that are visible only with color vision deficiency). But some normal trichromats can also read these hidden plates: https://jov.arvojournals.org/article.aspx?articleid=2135713

That's not how I read it. Normal trichromats see noise on L/(L+M) axis, for red-green color vision defective that axis is L/(L+L). We use S/(L+M) axis and luminance differences. Some normal trichromats can see through that noise.

To understand how it feels lets compare with a superior vision of birds [1]. "That bird is mostly black", I see what it does not see.

With normal vision colors pop out. I've checked once emulation, animal tongue is so red (displayed as hot pink), the brightest point on the picture. Meanwhile it is "just red" for me.

[1] https://www.google.com/search?q=how+bird+see&tbm=isch

Re: Color blindness

#70
Good to consider everyone when designing interfaces.

As for degrees, I had a Cub Scout making a craft project. He held up a pipe cleaner and asked "Is this green?" It was black. Jet black. I said "No, its black". Oh. He selected another (green) one and all was well.

So it can be complicated for some.

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