Was Vincent van Gogh color blind? (2012)

They're better at detecting camouflage than trichromats.

Do they have special ink and printers for color blind/ tetrachromats?

I would describe myself as a sort of green/brown colour blind - at least I know which colours cause me issues.

Turns out it disqualified me for around 70% of all jobs in the Air Force. Turned out to be a blessing in disguise because of the jobs left, they were the likes of Computer Systems programming, contracting, intellegence, etc. It made sure i wasn't going to be working in some warehouse doing electrical, or gaurding some gate as security forces.

> I am crazy about two colors: carmine and cobalt. Cobalt is a divine color and there is nothing so beautiful for creating atmosphere. Carmine is as warm and lively as wine… the same with emerald green.

> The Mediterranean has the color of mackerel, changeable I mean. You don’t always know if it is green or violet, you can’t even say it’s blue, because the next moment the changing reflection has taken on a tint of rose or gray.

They look incredible, and significantly more life-like in the simulated colorblind version compared to the regular version.

Quick excerpt of a letter to Theo:

"I still often run up against a blank wall when undertaking something, but all the same, the colours follow one another as if of their own accord, and taking a colour as the starting-point I see clearly in my mind’s eye what derives from it, and how one can get life into it.

Jules Dupré is like Delacroix in landscape, for what enormous diversity of mood he expressed in symphonies of colour.

Now a seascape, with the most delicate blue-greens and broken blue, and all sorts of pearly tones.

Then an autumn landscape with foliage from deep wine red to vivid green, from bright orange to dark havana, with yet more colours in the sky in greys, lilacs, blue, white, forming another contrast to the yellow leaves.

Then again a sunset in black, in violet, in fiery red.

Then again more capricious, like the corner of a garden by him that I saw and have never forgotten; black in the shadow, white in the sun, bright green, a fiery red, and then again a dark blue, a bituminous greenish brown and a light brownish yellow. Truly colours that can have quite a lot to say to one another."

Here's the most important part of that letter:

"Still, it doesn’t satisfy me. To my mind there’s far more behind not doing it in the local colour. True painters are the ones who don’t do it in the local colour — that was what Blanc and Delacroix discussed once."

At the time the impressionists were discovering that our color sense is counter-intuitive. They were developing methods of painting a color by using contrasts near a gray to imply the inverse color, etc. That's what he means by not "[doing] it in the local color."

You put red by gray and the gray looks green by contrast.

To look at those paintings and say "I guess he painted this way because he couldn't see the color right" is incredibly ignorant. His choices were deliberate and he documented them in excruciating detail.

Now, if only someone could filter it to simulate non-colour-blindness for me, so I can see what they see!

With protanopia, the L cone cell is affected. For deuteranopia, it's the M cone cell.

To me, one of the images clearly has a yellow color where the other image has a green-ish color.

The visibility probably depends a lot on your display color calibration and how fil spectrum your ambient light is. Incandescent "soft white" and modern imitations, common in household lighting, is usually yellow/orange.

I even overlayed the two images over each other and flicked back and forth between them.. they are identical

> Why is protanopia like deuteranopia? Red and green colorblind deficiencies (deuteranopia and protanopia) are very similar, as these cones often overlap. Therefore, protanopia and deuteranopia can often eliminate the ability to see both red and green, showing the world in vibrant blues and yellows, as well as very similar browns, oranges, reds, and greens.

> People with deuteranomaly and protanomaly are often incorrectly diagnosed collectively as ‘red-green’ colour blind because both types generally have difficulty distinguishing between reds, greens, browns and oranges. They also commonly confuse different types of blue and purple hues and many other colour combinations.

> The answer is that dichromatic colorblindness is imitated by assuming two of the three types of receptors receive the same light input. In deuteranopia, for example, the assumption is that the neural receptors expecting medium (M) and long (L) wavelength light are both receiving signals from cones with long (L) pigments. This results in the yellow you noticed. Note also that deuteranopia and protanopia don’t result in exactly the same hue of yellow because of the difference between their peak sensitivities. In one case it is assumed all signals are coming from L pigments and in the other all from M pigments.

Seems like there is more variation in chromes filters than the ones shown in the article.

BTW they look the same to me too.

In chrome: console > rendering > emulate vision deficiencies

Not sure what exactly happened, but if you search for this post through algolia, it shows the post being a few days old.

People with perfect pitch can be played a note on a piano, and identify it sight-unseen. "That's a C-sharp", they'll say confidently. Most others can tell if a note is higher or lower than another, or can pick an interval.

Regular colour vision is perfect pitch for colours. Most folks can identify a blue or a green in isolation, but some like me can only see relationships between colours (one is "bluer" or "greener" than another).

The linked article (which has very few pictures, this link to work by the original researcher has much more: https://asada0.tumblr.com/post/11517603099/the-day-i-saw-van... ) is about something else, namely a form of color blindness that distorts your vision in ways that are a lot less obvious than the way more common red/green or even blue/yellow color blindness.

I’m not an expert, of course, but to my layman’s eyes the “corrected” images look much, much better than the u corrected ones (you’ll need to see them indoors, however, on a reasonably good screen, to truly appreciate the difference). Uncorrected van Gogh’s work always strikes me as flat, lifeless and therefore amateurish. The corrected ones have much more depth and therefore, while garish, strike me as much more competent.