Category Archives: People

“Colourblind as all we are”

Are you living in the Hong Kong area? Riddick Ning contacted me quite a while ago as they were putting together an art show to raise the awareness of color vision deficiency. He wrote:

“Nice to meet you. I am a colourblind artist based in Hong Kong. This Apr/May I will be curating an art exhibition with the title “Colourblind As All We Are”, using new media art and a new approach to arose the social awareness in Hong Kong. I will be inviting people with normal vision but different profession to join the exhibition to crossover and jam art works, including video artists, graphic designers etc.

Your 50 facts comes in handy when I talked to those don’t know much about colourblindness. I want to ask for your permission allowing me and my team to translate, edit a bit to fit the Hong Kong audiences, and transform the information into graphics and text to post online and used in the artwork.”

This all sounds pretty interesting and I’m looking forward to see some pictures or videos of the event.

24th of May til 22nd of June 2014

Colourblind as all we are - front
Colourblind as all we are – front

Colourblind as all we are-02
Colourblind as all we are – back

On the back side of the postcard he writes:

“Although there are approximately 300’000 people in Hong Kong suffering from CVD, this number does not seem to alarm anybody in Hong Kong, including the Hong Kong government. To raise the social awareness of CVD, Colourblind As All We Are challenges audiences that we are all colourblind in an artistic way.”

Thanks for this new idea and effort and hopefully they really can raise the awareness of color blindness.

Was Vincent Van Gogh Colorblind?

The Hokkaido Color Universal Design Organization has a “Color Vision Experience Room” which filters out parts of the light to give you the impression of how colorblind people see the world. In this room Kazunori Asada spotted some paintings from Vincent Van Gogh and from there on the idea arose to make some tests, if Van Gogh might have had some form of color vision defiency.

Earlier on Kazunori Asada already developed a tool to simulate different forms of color vision defiency. With the help of this tool he was interested to see, if the impression of some paintings of Van Gogh will change, if they were run through the program.

In his article The Day I Saw Van Gogh’s Genius in a New Light he covers the following:

One of my friends who has protanomal color vision, a designer and painter, said this to me:

“It’s wonderful, isn’t it? We color deficient people, actually better than color normal people, understand van Gogh’s true nature and appreciate he is the genius of geniuses. In our opinion, van Gogh surely had color vision deficiency. Therefore, color deficient people can better understand his pictures.”

I considered this. After returning home, I viewed van Gogh’s works using the “Chromatic Vision Simulator” software which I had developed. However, the images simply lost their color and the sublime impression I got in the “Color Vision Experience Room” was missing.

Then it occurred to me to ask – Is my friend partially color vision deficient (anomalous trichromat)? Perhaps using a strong color vision deficiency (dichromat) simulation was the wrong approach. How about carrying out the simulation by removing only a specific portion of normal color vision, maybe then I could see van Gogh’s works in that light?

Hereafter two simulations of Van Gogh’s paintings. On the left side you’ll see the original, on the right side the protanomal simulation (also called red-weakness):

Van Gogh - Flowering Garden - Normal Van Gogh - Flowering Garden - Protanomal
Van Gogh - Starry Night - Normal Van Gogh - Starry Night - Protanomal

As I am also strongly red-blind I can’t see any difference in the paintings. Looking at them makes me think, that they look completely normal and I don’t see any very strange color arrangements in the paintings.

You can read the whole article of Kazunori Asada at: The Day I Saw Van Gogh’s Genius in a New Light. This article also includes some more paintings with their corresponding color vision deficient simulation.

Living with Total Color Blindness —Documentary Island of the Colorblind

Oliver Sacks: The Island of the Colorblind

Oliver Sacks is a physician, best-selling author, and professor of neurology and psychiatry at Columbia University Medical Center. In 1997 Dr. Sacks wrote a book about tiny Pacific atoll of Pingelap, where the genetic disease of complete color blindness (achromatopsia) is much more common than in the rest of the world.

One year after that BBC made a four-part documentary including the Island of the Colorblind. Hereafter you can watch this video, which is split into six smaller parts.

Watching this documentary you can learn a lot about color vision, how it feels to live with complete color blindness and of course a lot about the people from Pingelap.

Island of the Colorblind — Part 1 of 6

Island of the Colorblind — Part 2 of 6

Island of the Colorblind — Part 3 of 6

Island of the Colorblind — Part 4 of 6

Island of the Colorblind — Part 5 of 6

Island of the Colorblind — Part 6 of 6

If you want to read more from Oliver Sacks, you can visit his personal homepage at

Research Study Looking for Colorblind People around Oklahoma City

The company Terry Neese Personnel is looking for several people who are color deficient to participate in a study for air traffic controllers at FAA (Federal Aviation Administration, US).

As they are located in Oklahoma City, you should live around this area.

You’ll get a compensation of $25 per hour and shouldn’t be older than 30 years.

If you match the criterias and would like to participate, please contact Vicky at or call her at 405-942-8551.

$3.300 to Lessen the Handicap of Color Blindness

In my last poll I asked colorblind visitors and readers of Colblindor: “Would You Pay Money to Improve Your Color Vision?” During the ten days of evaluation 280 people joined the poll – thank you very much.

Many people who suffer from any form of color vision deficiency are looking for a possibility to improve their color vision or even cure it. It is interesting to learn what people are willing to pay to reduce this handicap and get a broader color sensation. Here are the results of the poll:

Would you pay money to correct your color vision deficiency?

Would you pay money to correct your cvd?

In the first chart I merged together all the votes which would pay from $1 to more then $10,000 to improve color vision. This gives us a broad view if people are willing to pay money at all.

The result shows, that less than 20% are not willing to pay any money at all to improve their color vision or even cure a color vision deficiency completely. Out of the rest around 60% would spend money for an improvement. Overall around one third would only pay if the actual treatment or used technique would completely cure their color vision deficiency.

How much money would you spend to improve your color vision?

How much would you spend to correct your cvd?

The second chart shows only the votes from colorblind people who are willing to spend money to improve their color vision.

There is a broad range of the amount people would pay to lessen their handicap. The lower end starts at something between $1 and $300 and the upper limit I suppose goes up to several $10.000!

If you look at the graph the votes are quite evenly distributed over the whole range. But on the other side there is something you could call a split between $5.000 and $10.000. I suppose this comes from the fact that some people above that limit are willing to pay almost any amount just to get rid of their color blindness. Below the limit of around $3.000 to $5.000 many people would pay some money but can also arrange themselves with their handicap.

If we strictly just take the lower limits of each range we get an average of around $3.300 which some colorblind people are willing to pay for an improvement of their color vision. This makes an overall amount of almost half a million dollars just for the people who voted on this poll! I wonder how much money you can earn if you really can cure color blindness…

Living with Color Blindness

“Which color is that?” is an often heard question if you are colorblind. You get used to it. You also learn how to handle it like most other difficulties which arise from your color vision deficiency.

I this article of the Color Blind Essentials series I would like to have a closer look at the every day life of a colorblind person and also at the impacts this vision handicap can have on your career choice.

Color blindness in everyday life

Most people think traffic lights are one of the biggest issue for everyone suffering from a color vision deficiency, but they are wrong. The colors for traffic lights are very well chosen and they are always arranged in a certain order. So this is not a problem at all for most colorblind people even if some states don’t allow you to get a drivers license if you are colorblind.

Bananas Big - Normal
Bananas Big - Deuteranope

Original and its color blind simulation.

But there are some real handicaps for people who are suffering from some moderate to strong color vision deficiency:

  • A Sunburn can’t really be seen, only if the skin is almost glowing.
  • If meat is cooked can’t be told by its color.
  • There is no difference between the colors for vacant (green) and occupied (red).
  • Flowers and fruits can’t be that easily spotted sometimes.
  • And you can’t tell if a fruit or vegetable is ripe or not yet.
  • Every electrical device which uses LED lights to indicate something is a permanent source of annoyance.
  • Colored maps and graphics can sometimes be very hard to decipher.

By far the most biggest issue is matching colors and specially matching clothes.

If you a have a color vision defect you can’t just choose flowers which fit together nicely, or a painting which fits with the furniture, or a carpet. You also can’t create a web site or an image with nicely matching colors. And you will never be able to easily match your shirt with your tie, your trousers with your shoes, your whole wardrobe.

In this case you need a pair of color enabled eyes which help you out. I often borrow the eyes of my wife and sometimes those of my son. They really help me a lot. ;-)

Choosing your career as a colorblind

A color vision deficiency often gets more attention when it comes to choosing a future career. Specially parents are very concerned about possible restrictions. But also young people ask themselves, if the job of their dreams will stay just a dream because of their vision handicap.

Professions that require good to perfect color visionAirline pilot
Air traffic controller
Police officer
Train driver
Some ranks in the armed forces
Some electrical/electronic engineers

Jobs which require good color vision can be split into two different categories. In the first of them color matching or color recognition is a main component of the job. This for example includes color quality control, art teaching, interior decorating and more.

This group of jobs is easy to decide about for colorblind people as each one knows best himself if he will perform well in such a profession or not. Most colorblind people can also accept this fact more or less easily.

The other category includes jobs which also require good color vision but only in support of the job itself. This group includes the job profiles of pilots, firefighters, police officers and more. These kind of jobs have the following facts in common:

  • Bad color vision is a security problem in this job.
  • Passing a color blindness test is required to qualify for the job.
  • The impact of a color vision deficiency is not well described.
  • There is no international standard on color vision requirements.

The points listed above unfortunately make it very complicated. Many colorblind people believe that they still could perform in such a position perfectly and that turning them down just because of their color vision deficiency is not correct. Some people even start thinking about how to cheat on such a test just to get through the exams and get the job of their dreams. But this is not the right way to go.

Here is my six steps plan towards your future career:







(1) Learn. During your time at school learn how you can handle colors. Learn about the severity of your color blindness and learn your special techniques to get around your handicap. This way you are very well prepared when it comes to choosing your future career.

(2) Inform. Get all possible information about the job of your dreams and possible handicaps for color blind people. You can get information from a prospective employer, from special authorities like the FAA for pilot candidates and of course from the internet. It’s important to check your local requirements as they can vary between different countries.

(3) Talk. Try to find some people who are working in this job and talk to them. They will know the best if there are special tasks which might be a problem and you will know from your personal experiences, if you will be able to handle and also most important if you will feel comfortable in such a position. First check your relatives, ask around in your neighborhood, maybe you will find somebody at the college and otherwise I’m sure you will be able to find somebody online who will be happy to help you out. Just check forums where those people could hang around.

(4) Communicate. Don not try to hide your color vision deficiency. Be honest and communicate it if it might be a problem. Of course you only have to do this if color vision could be a possible handicap. But it is important to inform your prospective employer what you learned about the job to be done and how you overcome those handicaps despite your imperfect color vision.

(5) Go for it. Don’t forget to take the last step. Do the required tests to learn more about your color blindness. You might pass without any problem and you might fail. You maybe also like to try different employers as there are in most jobs no national rules concerning color vision deficiency.

(6) Discuss. Did you fail the color blindness test and did they use the Ishihara plates or some similar form? Read the chapter about color blindness tests to learn about other possible tests. This should help you to start a discussion about the used test and if maybe this test was just to restrictive. There are many different tests available and sometimes it would be even much better if your prospective employer would just check possible job restrictions and if you can handle those or not.

And please don’t forget the fact, many people have some form of handicap which is a burden and sometimes becomes a big obstacle. Get used to your color blindness and try to accept that moderate to strong color blind people shouldn’t dream to work for example as a pilot or a professional firefighter. If you can’t accept this, don’t try to cheat on the tests but start a discussion about it!

Red Apple - Normal    Red Apple - Protanope

Left: normal red apples — Right: colorblind red apples

We are colorblind. We can’t name colors. But we can handle most situations perfectly even if we don’t know correctly which color it really is.

In the next and last article of the Color Blind Essentials series we will learn if there are any possibilities to cure color blindness.

Photos taken by clairity and Muffet.

Richard’s Life as a Color-Blind

Richard was so friendly to write his answers in detail on The Color Blindness Project Questionnaire. Thanks! I thought putting this together into an article by itself makes it more public to other interested readers. So the here are his answers:

When did you first discover you were colourblind?
My parents suspected when I was about 4. I could arrange the vivid primary coloured blocks of my toys, but anything less than vivid, crayons, clothes food, I was misidentifying what colour they were.

A trip to The Natural History Museum in London with an exhibit on the eye, and on colour vision, confirmed this when I did all the classic misreading of the Ishihara test. By the time the formal colour test rolled around at school, it was pretty much a foregone conclusion.

How did you discover you were colourblind?
Well aside from being told the story above, it was for me, being simply unable to colour things in correctly or recognise colours.

  • For years, my anti-smoking posters at school had cigarette butts in brightest green.
  • My Union Jack was easy to identify: It was purple and orange.
  • All my drawings throughout my youth were in my own special palette.

And it continues. There was a lot of hoo-ha in the news recently about our beloved British brand Cadbury being taken over by US Multinational Kraft, “the famous purple wrapper” the newsman announced. — Purple? I’m 29. I had no idea. I thought it was blue.

What are the issues/problems you have faced being colourblind?
Well disability, let’s just define that, depends on how society is organised. What I have is an altered sensitivity to the spectrum, this only matters when things are categorised by colour, then I am adrift in a canoe without a paddle.

An example, only a trivial one, I was attending a job interview and the waiting area was a calendar which denoted all the religious festivals of about 10 different faiths. The key was colour code and the days and months were festooned with little coloured dots, which were meant to be wonderfully informative about which religious festivals fell on which days. I couldn’t tell them apart. Moreover if someone had been there and said what about that one, what colour is that? I’d have been guessing. I’ve gotten pretty good at that: guessing. And false positives are self correcting.

I see what I think are the colours but I have very little ability to tell them apart. I’m a diagnosed protanope so very strong red blind, and this cuts a swathe through my sensitivity to reds, greens, browns, yellow, oranges, and the pseudoisochromatic colours with which I can (and do) confuse them.

Thus, red can appear black or dark grey, but not always. Blood for instance to me looks brown, very dark. I do see a red – coca cola cans for example, but I’d bet what I think of as red probably isn’t and is very much dependent on the context. Take my coca-cola red and put it on a snooker table and I bet I’d confuse that red with something else. That’s why grass is green. Of course grass is green. But green in other contexts is where hue, and brightness combine to confound me.

  • Blue and purple, covered that one.
  • Orange and certain browns.
  • Yellow and green.
  • Grey, certain greens and pink are completely interchangeable.

Everyone all thinks traffic lights are hard, they aren’t – not really. You learn them by sequence. What they aren’t is the right colours. The two red and amber, to me look like slightly different species of yellow. And the green at the bottom, is white – it looks like an ordinary light bulb.

Of slightly more difficulty are brake-lights. Recognising those from tail lights is hard. I’ve hit the brakes hard, once to often now to believe that I’m not just a bad driver.

How did you overcome the shortcomings?
I have very sympathetic parents. My brother is the same, so they coped with both of us down the years.

Teachers, I think don’t get it. And I don’t blame them. Colours are a second alphabet. People assume you know what they are talking about. Even when you tell them, if they remember at all, it’s rare that they alter their behaviour.

And what do you tell them?

I’m colour blind?

What you can’t see colours? …yes..but..I..can’t tell them apart.

What colours’ this [ ]* then?

*[ ] insert nearest object here.

and that’s how it usually goes.

Colour vision deficiency takes longer to say, as does the explanation, and I prefer it but I don’t think it helps people understand. I’d prefer they had a solid grounding in colour-theory instead.

It’s taken some time for me to get my head round it, but I am not sensitive (cannot see) certain hues. The hues I can see are modulated by brightness. A sufficiently bright green is as yellow to me. Purple’s an interesting one, because what is reflected is blue and red light, I can detect the blue, I am insensitive to the red, all purples are species of lighter or darker blues.

My solutions are if it’s important that it’s coloured I label it. It is simply no good relying on me to see a colour and recognise it. I need that second level of information like a name written down. Second, I ask people. I’m pretty up front about saying I’m colour blind – I can’t see that. What colour is it? That usually works, with the above caveat that no-one has any idea what I’m actually talking about.

In my own life it was pointed out to me, that I shop for clothes by texture, I’ll go around scrunch up shirt sleeves and jumpers to see how they feel, what they look like is secondary. My wardrobe also reflects a certain bias. Lots of blues (which I can see) Lots of dark colours, greys, a few greens (definitely green not pink) and black.

What else can be included/excluded in the guide book for parents other than the ones described above to make it more comprehensive?
Oooh. I wouldn’t want to frighten them. An introduction to Ishihara—as that is what they will likely encounter and have to sit with their child through, what it means and how it diagnoses.

I think I would personally want an easy to understand overview of what colour is (wavelengths of light), the idea of a colour gamut, a colour space, (RGB etc). And then how colourblindness changes that. How the Ishihara dots are painted in the pseudoisochromatic colours that exist in those spaces for people like me who lack sensitivity to one of the spectral colours of light.

What it means: not that my world is uncoloured. I swear to you it isn’t. I just have no idea what those colours are called. It’s rather like having a virtuoso chef who can create all the world’s dishes out of only three ingredients. A little of this, a little of that, a pinch of the other and *foompf* Egg salad nicoise. And then taking away one his ingredients. Yes he can still make all those different foods in all the variety, but without that extra thing, everything he makes is just the little bit more bland and samey. You can’t really tell them apart anymore. That would be flavour blindness. I’m colourblind in the same way.

Thank you very much Richard for this great insights.

PS: Richard updated his answers and polished them even more. You can find his latest answers on the color blindness survey at Further Adventures in the Land of the Colourblind

The Color Blind who Feels Colors — Synaesthesia

I am colorblind and don’t have a very broad color spectrum. Because of that it is even harder for me to believe, that there are some people who not only can see colors with their eyes but in a way feel colors or see them with an extra inner eye. Every thing, even abstract terms, letters, numbers, just everything is associated to a color or several colors.

Colblindor Synaesthesia
As a word it would be a mixed pink-yellow-white color.

Ying, a women who is gifted with this very special ability, contacted me a few weeks ago and I could learn from here explanations a lot about grapheme (color synaesthesia): An individuals perception which is involuntary, consistent, and memorable associated with the experience of colors.

Basically I never really thought about this, but most things (real, abstract, imagined) has a color to me since I was a small child. The assignment of colors seems to have no reason or any rule at all, yet remain consistent. i.e. The days in a week: Monday is silver white, Tuesday is grayish blue, Wednesday is deep pink, Thursday is green, Friday is mustard yellow, Saturday is red, and Sunday is pale yellow. All the numbers have a color, too, as well as things like directions, months, abstract things like gravity (do you know gravity is steel gray to me?)…etc. I didn’t think it’s weird until my friends said it’s weird and they don’t think like that. I can speak three languages and the colors of things don’t always match in different languages. i.e. the word “wife” in English is a gray color, it’s equivalent word in Chinese is a dark red color. I can’t really explain them. Like I can’t explain why bananas are yellow, well because they are yellow as a fact.

I added a few more questions to this first introducing statement so I could learn more about synaesthesia. Here are a some more of those very interesting facts about it.

Colblindor: What about some specific words. Do they always have a specific color? Is angry really red, calm green and hot red, cold blue?
Ying: Ok about the colors of words: yes those words definitely have consistent colors to me. I have to mention that words have no colors until you understand them, and I didn’t start English until my late teens. My sense of colors might be off from authentic English speakers who learned them as little kids. :) Anyway, hot is orange to me, almost burnt (dark) orange, cold is steel gray, angry is a whitish blue, same color as “air”, calm is a watery dark blue. The thing is, many words don’t have a solid color, they frequently have 2 or 3 colors and have a swirly or mottled look. Only very simple things like simple digit numbers or the alphabet have a single color.

Colblindor: Do you in some way “see” this colors or more like “feel” them?
Ying: I’m a very visual person, so I would say I rather “see” them then “feel” them.

Coblindor: Do you think it is a gift, a handicap, or something you would prefer not to carry around with you?
Ying: It doesn’t affect my daily life much at all. I’ve only ever brought it up a few times with some very close friends and was surprised that they don’t have it. It might help me remember things and names better. I’m not sure if it has any other use.

Colblindor: Do you know other members in your family who are feeling the same?
Ying: I never talked to my parents or siblings about this so I don’t know if they have that or not.

Now there is no obvious relation between color vision deficiency and grapheme. What if you combine both of them? — You wouldn’t be really able to see all colors with your eyes but feel and automatically associate colors to everything. Could you “feel” more colors than you perceive?

Fact is that Yings both sons claim to have also an inner eye which relates colors to things; and one of her sons is colorblind.

If you want to learn more about synaesthesia read this excellent description from Cassidy Curtis at There is also an interesting site from the University of Sussex about their ongoing synaesthesia research.

Interview with the Author of Colour Blindness: Causes and Effects

Colour Blindness - Causes and Effects
Colour Blindness – Causes and Effects

The book Colour Blindness: Causes and Effects is one of my favorite sources for all kind of information related to color vision deficiency. About one week ago I was contacted by the author of the book Donald McIntyre.

I invited him to join us for an interview and I am very pleased that he answered me back so quickly. Please read on and learn about Donald’s color vision deficiency—and more.

Colblindor: Are you suffering from any color vision deficiency yourself?
Donald McIntyre: Yes, I am a protanope. That is to say, I completely lack the set of cones in the retina that are sensitive to long wave (red) light. Reds appear very dark to me and I have great difficulty distinguishing among the range of reds, greens and browns (plus several other confusions).

Colblindor: What inspired you to write a book about color blindness?
Donald McIntyre: I have been aware of my colour vision deficiency since childhood. When I tried to find out more, all I could find were simple one page magazine articles, or highly academic research publications. There was a need for a book that explained colour vision deficiency to the ordinary reader, but in sufficient depth to answer the many questions that arise. Since the book didn’t exist, I decided to write it myself.

Colblindor: If you would write it again, which aspects would you highlight more deeply?
Donald McIntyre: It would have been nice to have time to find more anecdotes about the experiences of colour-blind people in different walks of life. Has any footballer ever passed the ball to the wrong side? I couldn’t find one to speak to.

Colblindor: Do you think there will be a treatment of color blindness in the near future?
Donald McIntyre: Unfortunately not. The computer-based simulations can give a very good idea to the colour normal of what we colour defectives see. But not the other way round!

Colblindor: What do you think about the fact that many colorblind people can’t become pilots, police officers or firefighters?
Donald McIntyre: The problems with colour vision deficiency become serious when a person has to make a critical decision on their own, especially where safety is involved. For instance, there are successful colour-blind electronic engineers who carry out development work in the lab. However, no colour-blind engineer should install or repair wiring in the field.
An important and often overlooked fact is that there are degrees of severity in colour vision deficiency. Protanopia (my sort) is the worst. At the other end of the range of severity, mild deuteranolamy involves a slight shift in the sensitivity of the middle wave cones and may not be a problem in many jobs. The commonly used Ishihara test is very sensitive and will pick up the mildest defect. If a person feels they have been unjustly barred from a profession, they can ask for a more detailed vision assessment and argue their case.

Colblindor: What would you tell a person who just found out that she is colorblind?
Donald McIntyre: First of all, it’s not that serious. Many people do not realise that they have one of the milder forms of colour vision deficiency until adulthood, perhaps when they are tested when applying or a job. It is worth finding out about colour-blindness at a young age, to avoid training for a profession that may produce problems later on. I would not go along with those who say the colour deficient view of the world is “equally valid”. We do lose out on some of the pleasure that colour can give, but there are plenty of other delights in the world.

Dear Donald, thank you very much for your time, for joining the interview and of course for your book.

The Most Frequently Asked Questions on Color Blindness

Since I started Colblindor more than two years ago I posted 233 articles, count as of today 623 comments and I was contacted more then 350 times—with increasing frequency. So I thought it is about time to write an FAQ on color blindness.

So far I put together the six top questions I get asked almost on a daily basis.

You can find the detailed answers at full length under the separate page Color Blindness — Most Frequently Asked Questions. In this short article I will only feed you with some very compact answers.

FAQ Color Vision Deficiency

  • Is there a cure for color blindness? — No. There are some scientists experimenting with color vision genes, but this won’t be available in the near future.
  • Can I correct my color blindness? — No. Neither glasses nor lenses or any other tools can correct it. But some of them may shift your spectrum of color sensation.
  • How can I pass the Ishihara test? — If you are colorblind, you can’t pass it. Some lenses might help you but are usually not allowed during testing.
  • Is my son colorblind? — Don’t be concerned. Wait until he goes to kindergarten and then ask yourself this question again.
  • Can women also suffer from color vision deficiency? — Yes. About 0.5% of all women are colorblind; 16 times less than men.
  • Which type of color blindness am I suffering from? — Only your eye specialist can tell you that. But some online color blindness tests might give you some clues.

If the answers were just to short, read them at full length. But if your question isn’t mentioned at all, don’t hesitate to contact me.