This is interesting, but let me give you the perspective of someone who is red-green colorblind (though, I just noticed I can't see anything in this image that's supposed to test for Deuteranopia http://en.wikipedia.org/wiki/File:Colorblind4.png - but testing for colorblindness on a computer monitor is far from accurate).
It's not that big of a deal.
Really. On the list of things to worry about in your web or software development, I'd place "worrying about how colorblind people see my website" pretty darn near the bottom.
Here's a comprehensive list of the ways that my disability has caused me to suffer:
* I'm really awful at picking strawberries and cherries. Dark red fruit against green foliage does not stand out at all to me the way it seems to for other people. Before she knew I was colorblind, my mother just thought I was lazy and/or eating all the fruit I was supposed to be picking.
* Occasionally, I'll buy/wear clothes that don't match. Because I think they're brown, but really they're a subtle shade of green.
* Sometimes, I'll call something brown or grey or blue that's really red or green, and people will find it hilarious.
* When people learn that I'm colorblind, they spend several minutes pointing at things and saying, "Can you see that? What color is it?".
Really, that's about it.
I vary rarely come across things on my computer screen where the functionality is impeded by my inability to distinguish color. Though, I've got to admit, the BBC's football table example is a pretty great example: http://wearecolorblind.com/example/bbc-online-football-table...
I suspect that things are different for people with different levels of colorblindness, but then you're talking about ~1% or less of the population.
My favourite brown shirt is green. Normally, I don't like brown, but I like that one. I wore it for years thinking it was brown until I said something to my wife that made her look at me funny (ier than usual).
My colour confusion is particular: Certain pinks and purples are grey, certain colours aren't quite right (like my "brown" shirt), and I cannot see red unless it is "bright enough". I see the red of an apple just fine, but Mars has always been a faint object of uncertain colour. I always thought people were waxing poetic until I learned of my colour confusion.
I really do prefer that term, by the way, not for any reasons of political correctness, but because it is far more accurate, and gets people inquiring as to just what I mean. If I say "colour blind", they assume red-green - I have no problems with red or green or Red Green, and see traffic lights the way FSM made 'em.
The only time my colour perception has caused me problems at a computer is when someone insists on pink fonts on grey backgrounds. It's not just that it's hard to read, it hurts. It really, really hurts to look.
For me, there is minimal contrast and no edge definition, so the letters float and shift on the screen and it is painful to look at. Highlight the text, flip the contrast, readability restored.
The only situations I've really run across problems with color is with labeling or tagging, if colors play a critical role in distinguishing the tags. This was particularly bad in Trello before they introduced a color-blind mode. I actually dislike the way they handled it. Trello only allows 6 predefined colors for labels, and the colors they picked were particularly bad for those with red-green colorblindness (I could barely distinguish between the blue and purple, and could distinguish the red and orange side-by-side but not identify in isolation); they then introduced a color blind friendly mode that adds unique patterns to the most problematic colors (blue, orange, green). What bothers me about this is that it would have been extremely easy to just pick 6 colors that weren't problematic (red, dark blue, light blue, yellow, black; there, that took me under a minute, and the least you could do is consult a representative of 8% of your users for 30 seconds). Once they realized the colors they'd chosen were a problem for red-green color blind users, I understand why they introduced a new mode instead of changing the colors for everyone, since that would disrupt and confuse many people ("I don't know where I put the card, I just made it purple, and now there's no purple!"), but the problem could have been much more elegantly solved with a bit more forethought.
Summary: color blindness is only a handicap in situations where identifying color is critical. Situations like this aren't that common, but there are cases, and when you're going to put significant thought into picking a color palette it just comes off as lazy and irresponsible (unless there really isn't a good solution—e.g., picking a palette of 50 colors).
Pointing at things asking what colour it is, always happens to me too.
I recently downloaded a handy app, that lets to point your camera at objects and tells you the colour. It's called kleur (iOS), it's pretty cool, has 1500 colours but it's not 100% accurate.
Diclaimer: I have full-color vision, but with color blindness there are (roughly) two dimensions of color, whereas most people have three (and a black and white photograph has one). What this means is that with 1D color, you can sort all of the colors you see into a line -- dark to light. With 2D color, you can sort all of the colors you see on a flat plane. With 3D color, you require stacking colors.
Now, there's plenty of animals out there that have more than 3 dimensional color (they have more than 3 types of cone cells). So two colors that look the same for a normal person will look completely different for an animal. Some octopi have eleven dimensions of color! To them almost every human would be severely colorblind.
For most people, yellow photons striking their retina will produce the same effect as a combination of red and green ones. If you look at this cone cell response graph (http://upload.wikimedia.org/wikipedia/commons/1/1e/Cones_SMJ...) you will see this is because 520 nm + 640 nm light can give the same effect as 580 nm light with the appropriate intensities.
Having 3 cone cells is the reason that most electronic equipment has 3 types of subpixels (red, green, and blue). If you take the colors of these three subpixels, locate them on the CIE 1931 chromaticity diagram (http://upload.wikimedia.org/wikipedia/commons/b/b0/CIExy1931...) and draw a triangle to connect the points, this triangle is the color gamut of the monitor. The more types of subpixels you add (or the further apart they are in color), the more colors your monitor can reproduce. This is why Sharp's television with that 4th yellow pixel can reproduce more colors that humans can see.
It's thought that some people might be tetrachromats. They have 4 types of cone cells because of a genetic mutation. There's still some questions on how this extra information is processed by the brain, but there's a chance that for these people almost everyone else seems colorblind. They are able to distinguish two colors that everyone else cannot. This also means that television won't reproduce colors correctly for them, and it won't look natural.
That's interesting about tetrachromats. I knew a lady when I was a kid who claimed she couldn't 'see' an image on TV, that it was all just garbage to her. I'd always just assumed she was either crazy or making some weird kind of statement. Maybe not!
That would have to be something else. The effect of an extra cone on watching TV should be far less severe than a normal eye's view of black and white.
A JavaScript widget, browser plugin, or Photoshop filter to colorblindify, in various types, a webpage so that designers can check for usability would be useful.
EDIT: Actually, what would be more useful are colorblind OS X color profiles and an easy way to switch between them.
The website just has a couple of articles but looks promising.
I'm color blind and know the frustration to not be able to play some videogames or read charts which use very similar colors (at least to me).
A lot of people don't even understand what color blind really is, it's a funny thing to explain what it is and joke about it with new friends / coworkers when the subject comes along.
At least my coworkers now ask me first when choosing color coded post-it for the current project ;).
A lot of people don't even understand what color blind really is
Too true. Two otherwise sensible, college-educated friends of mine once insisted that they'd be able to tell how my eyesight is different if I sat down and drew what I see out of the window. Using pencil crayons that presumably pierced through my colourblindness. I literally could not find a way to explain to them why it made no sense.
"No, but we'll cover up the writing on the pencils so you can't read what colour they are"
EDIT: I realise I misrepresented the scenario. This wasn't talking about colour-blindness specifically, but in more of a "maybe the blue you see is my red" scenario.
Suppose you were red-green colorblind, and there was an apple tree with green "Granny Smith" apples outside your window.
You can't tell if the leaves on the tree are red or green, but using common sense, you guess that they are green, and color them with the green pencil.
You can't tell if the apples are red or green, but using common sense, you guess that they are red, and color them with the red pencil.
"Ah ha", says your friend, "you colored the apples with red when they are actually green. You must be red-green colorblind"
Some color blind people are more affected than others on their same color blind group.
In my experience doing an Ishihara test (http://en.wikipedia.org/wiki/Color_perception_test) whith someone else while telling them what are you seeing on each pod does wonders to make them understand specifically what shades of color cause you troubles, that's how my wife got to understand my color blindess.
There's also the fact that the ability to discern two colours depends on the two shades involved, and the shades that nature presents are probably different to the ones chosen by Faber-Castell. Also, when I was a kid I could tell the purple pencil from the blue if I held them together, but had trouble if I had just one on its own. (Still true today but I don't come across colour pencils so often...)
Which seems to suggest that I am green-blind, but not red. With 1/7 wickline, but I have no idea what that means (suspect it has been lost in translation somewhere)
This test seems to be flawed. I just did this test with four people and we all agreed that their correct solutions are sometimes wrong. Is an expert here?
Sorry, I edited my post to reflect the fact that I misrepresented the scenario. Though it started as a discussion about colour-blindness, it developed into a more general "what if my blue is your red" discussion. In that scenario, the red and greens on the tree would be matched exactly to the reds and greens on the pencils- there's no way to know if I'm seeing something different.
Thanks, I made the site and write the articles. If you (or anyone else) has any recommendations for articles or examples of what doesn't work for you, that would immensely help :)
I use Flux right now to automatically dim/brighten my screen based on the time of day. Wouldn't it be a simple matter to use a similar program to alter the colors on screen to things that are distinguishable by a particular type of color blindness? This seems more efficient than every website reducing their palette to an arbitrarily low common denominator.
I remember reading that some people who are color blind have an exceptional sense of contrast such that camouflage which fools normal sighted people is immediately obvious to some color blind people:
With that in mind, are there any simulations of color blindness that take this into account, actually capturing the source image differently using a modified sensor? Most simulations are essentially taking a photoshop filter to an image that was captured on an RGB sensor.
Yay for this site! I'm somewhat seriously colorblind, and have a page on my personal site with a bunch of examples that do a good job of illustrating the difference between what I see and what other people see: http://www.robsheldon.com/colorblind/
One of the examples is a color-coded map from somewhere which would be nearly useless to me.
The colorblind simulator only works if you have normal vision. Is there a color corrector simulator for certain types of colorblindness? e.g. Show colorblind people what the colors look like to the normal viewer.
I'm no expert and I've only really glanced at that, but doesn't look like it shows a colourblind person what colours look like to others, it just changes the colours of something to different colours that stand out better against each other.
For that matter, unless someone either goes from normal to colourblind, or colourblind to not, is it actually possible to ever do this? Assuming the transformation isn't possible... how do you describe "red" to someone who can't see "red"? Even if you find the exact colour that, for a colourblind person looks like "red", how do you know you've found it, how does the colourblind person know?
As I was ranting a bit about Fog Creek's choice of label colors in Trello (http://news.ycombinator.com/item?id=4330851), I started to wonder: do development shops of 30+ people typically not include anyone who is red-green colorblind? Typically all that's required is to show someone a screenshot and say "does this work?". In the case of Trello labels, I have to assume that no one on the team at Fog Creek was colorblind, and that (i) the palette choice was done lazily, (ii) there was no one with red-green colorblindness at Fog Creek to do a quick "do these work?" check, or (iii) there were very strict design restrictions on what colors could be chosen to fit in with the rest of the site's aesthetic (personally, I think this is a bit silly, because the wacky patterns of colorblind-friendly mode clash a lot with the rest of the site's design, but 92% of users seeing a non-clashing experience may have taken priority). (ii) seems the most likely option. As a left-handed colorblind redhead, sometimes I take my 'deficiencies' for granted, but that just seems odd.
The biggest irony? Assuming statistical independence and that 8% of the population is colorblind, there's an 8% chance that a group of 30 people would not include anyone with colorblindness.
The worst colorblind experience I've had was playing basketball against a team with uniforms I couldn't tell a color difference. I had to focus on the style and typeface difference, as well as if I recognized the person or not. Extremely frustrating.
Second worst was teachers in elementary asking why the grass was brown and water was purple in my drawings. Huh?
Sweet, I am currently preparing a topic for my bachelor thesis and it will be something about cartography and colorblindness. Probably something with OpenStreetMap.
I was wondering where I could find people to test example maps etc on, guess I found a good starting point. :)
If someone has major color vision related gripes with any big maps or map services, I would love to hear about it. Not worth pouring out your heart though, keep it short so you do not waste your time in case I already noticed or thought about it.
Google maps used to use green or red lines in custom created maps. In satellite view that color had a very bad contrast with the surroundings, especially area's with lots of (green) nature in it. They now use a bright blue, never had any problems with it.
The new bike navigation feature is a bit more difficult. The legend is hidden in it's initial state, making it difficult and confusing to determine what colors are used for the different lines. After checking it appears that they are using a solid black, solid green/red and a dashed green/red line. Works pretty well, but in absence of the legend there is no way of knowing of you're missing something. Minor problem I'd say, but still :)
If you'd run things by me or get in contact with other colorblind people, shoot me a message via twitter (@wearecolorblind) or via the contact page on the website!
While it only rarely comes up, my specific form of colorblindness (protanomaly) results in red highlighted text looking like normal black text. This has made using some websites exceedingly difficult/impossible for me to use (www.readthekanji.com comes to mind). According to wikipedia, only about 1% of the male population has this form of colorblindness though, so you aren't looking at truly significant numbers affected.
It's not that big of a deal.
Really. On the list of things to worry about in your web or software development, I'd place "worrying about how colorblind people see my website" pretty darn near the bottom.
Here's a comprehensive list of the ways that my disability has caused me to suffer:
* I'm really awful at picking strawberries and cherries. Dark red fruit against green foliage does not stand out at all to me the way it seems to for other people. Before she knew I was colorblind, my mother just thought I was lazy and/or eating all the fruit I was supposed to be picking.
* Occasionally, I'll buy/wear clothes that don't match. Because I think they're brown, but really they're a subtle shade of green.
* Sometimes, I'll call something brown or grey or blue that's really red or green, and people will find it hilarious.
* When people learn that I'm colorblind, they spend several minutes pointing at things and saying, "Can you see that? What color is it?".
Really, that's about it.
I vary rarely come across things on my computer screen where the functionality is impeded by my inability to distinguish color. Though, I've got to admit, the BBC's football table example is a pretty great example: http://wearecolorblind.com/example/bbc-online-football-table...
I suspect that things are different for people with different levels of colorblindness, but then you're talking about ~1% or less of the population.