h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

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 Ishrara 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?
as a child, navigating, identifying, naming, differentiating colours etc..

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? *
ways/solutions you found helped you in the process? how? who helped you?

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?
Well..no..or …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 ishara dots are painted in the pseudoisochromtic 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.

Well said

The Ishihara test, also known as 'pizza with olives'. I rmember long ago at school taking the test, and wondering why my schoolmates were saying numbers while looking at the pictures

Probably though my colourblindness had been detected before, when I insisted calling a foam ball my bros and I used to play with 'the green ball' when they called it 'the blue ball'. Or the other way round.

This is the questionnaire if you want to go fill it in for yourself:

http://spreadsheets.google.com/viewform?formkey=dE0tT19HZUE5RzJqemF3Wk9lVHVQWEE6MA

and the blog I took it from

http://www.colblindor.com/2010/01/17/the-color-blindness-project-questionnaire/

I was once sitting at a table with my parents, my sister and her husband, my cousin and her boyfriend. I was the only male there who wasn't colourblind!

My cousin's boyfriend had an iPhone app which simulated colourblindness. It was quite interesting.

TRiG.

I look at those simulations and don't see much of a difference.

And then I think "oh yeah..."

Clive, how about submitting what you wrote (no, not that, that) to or Underguide?

I tend to get a bit flummoxed when I show people images which I ran through colourblindness simulators. They usually go, "what, you really see like that?" or "but how can you do if you cannot distinguish green from red?", etc.

Well, to the first question, I do like I've always done, and for the second -- under circumstances I can distinguish the colours, but sometimes I just cannot say which is which. That seems to mystify them colour people, ha!

Quite Interesting Clive!!!

And very informative.......

Is it true that there is a very acute form of colour blindness that leaves the sufferer seeing in monochrome only??

Seem to remember seeing the factoid somewhere!!


(Some smileys must confuse you!!)


GT

Yes. Very rare. It means your missing all of your colour receptors.

I am missing only one the long wavelength (red) cones. The greek is for for first, second and third So I am a Protan-ope, red-blind; there's also deuteranopes (green-blind) (mid wavelengths) and Tritranopes (blue blind - they can confuse blue and yellow. No I don't understand that one either ) (short wavelengths)

Can also come about by a brain injury.

I tend to think colourblindness simulators don't actually get it quiet right.

Yah they filter out the right shades and so on but something is always off about them to me.

What they are missing is how indeterminate colours are. It's a hard idea to get across but I look at a colour and I'm lost. Is it grey or green...wait maybe pink um.. green...no grey!

I've got no handle on telling them apart I have to go by their relative brightness and context.

I am most of the time or comparative guessing by this point...is it purple? oh it is purple! I was right but until it was confirmed I could have gone either way.


So the question "wow do you rally see like that?" No not really my world is completely coloured, It's not like there's no read I can see but what I see as red is very very similar to my browns and my greens and people, attach significance to colours which I can't tell apart or to put it another way my world doesn't look weird. Everything is completely normal, but I don't know what names to give to them because they are interchangeable. It's normal I make these mistakes or you waft an Ishhara plate underneath my nose and I'll get it wrong.

And that's when you realise you are living in a world of altered perception.

Confusion of blue and yellow?

Can be explained Clive. The three primary colours as far as TV/PC displays are concerned are red, blue and green. You can make up all the colours of nature out of those three 'primary' colours, as colours are mixed subtractively by the electronics..(Long wavelengths 'subtracted' from short ones)...(Blue + Green = Yellow)

With hues, as in a paintbox, the primarys are red, yellow and blue, and mix additively... (Blue + Yellow = Green)

Hope that is not too confusing!!



GT

>What they are missing is how indeterminate colours are. <

An example:

Bowel of fruit - through a simulator, and people will go "Urgh! That orange is green!" and I'll go: "Is it?"

Oh I meant I can't imagine the experience!

Probably I suspect because lacking red, and being a bit green weak -blue is my strongest colour, and yellow is it's opposite. I think that's just personally thing I can't imagine confusing them. I can imagine it possible - Oh can I do that - but I can't actually imagine it.

(Self tests always place me as protanope with mild deuteranomoly - interestingly, the red receptors peak in sensitivity at yellow which means my spectrum skewed through the reds, orange yellows and tapers out into the greens )

I did have a guide entry going on this but it stalled.

Just had a thought pal, and I am confused......

Why don't hues (paints) mix subtractively as light does????



GT

Tough to explain at midnight - ask me again in the morning.

I have had some thought provoker , and have remembered the answer....

Again, it is to do with light!!!!!


Paints, (hues) ABSORB all light frequencies falling on them, and REFLECT the frequencies that they are designed to reflect, thus giving the 'colours' that we 'see'.....

BTW.....

Did you know that light is simply part of the electromagnetic frequency spectrum???


It starts at 0Hz, climbs through audio frequencies, passes into ultrasound, (that dogs hear, but we do not!), onwards to radio frequencies, then up and up through RADAR (1000MHz to 10,000MHz), carries on and on.

Now the frequencies start to run out of control, so I switch to wavelength, (distance from crest to crest..)

The far infra-red (the bit of sunlght that feels warm) starts at around 100 micrometres. Visible light, 1 micrometre, or 10,000 Angstrom Units (deepest red) to 5000 Angstroms (deepest purple)....

Now we get to the dodgy stuff.....

Ultraviolet starts at around 1000Angstroms.....

The wavelength is now approaching the diameter of a cell. This is why we burn....

The energy cannot be dissipated, so is damaged...

UV ends at about 100Angstroms, and we enter X-Ray territory....OK in small, measured doses.....



Do we go further??

Yes we do....

At 1Angstrom, we are into Gamma Rays...

These are so energetic, and have such a short wavelength, that they are capable of knocking off atoms from DNA....

It is known to us as 'Radiation Poisoning'......


What comes after Gamma Rays??????


The Warlords have not found out...........................................................................................................................................................................................................YET!!!!!



GT

Hi Clive,

Found your journal entry interesting reading. I'm not color-blind, although when I was a child, my mother had me convinced that I was. She based her conclusion on my inability to tell teal from sea-foam from aqua or red-orange from orange-red or burnt umber from all the other shades of brown. (I thought she was putting me on.)

Years later, I took a series of aptitude tests, which included tests for color perception. In one test, I was directed to arrange a set of painted pegs from red to orange, and in the other test, a different set of pegs from blue to green. Based on my (rather low) score, I have somewhat lower than average color perception, and accordingly was advised not to pursue a career in interior decorating.


HN

low average might be a protoanomalous result: a weakness (as oppose) an absence of red sensitivity.

I know I'm the other kind because there are a couple of plates, in the Ishihara, right towards the middle which are kind of charcoal and slate grey - those are the protanope plates - and there - I am told - some numbers in there that should stand out as bright as buttons.

And I can sit and stare at those things all day and they never resolve themselves into anything like numbers.

The Ishihara dots is only one kind of test though sounds like you were doing a Farnsworth Tab Test.

Was it anything like this:

http://www.colblindor.com/color-arrangement-test/

I was the 1st to comment on this page, so we can compare scores!