Quick tool to check contrast sensitivity for different colors

async

I've been looking into how the different cones work together, and what compounds affect them, Partially inspired by a few experiences where bad screens cause color shifts, and that some people seem to have more issues with displays that have redtones, and some have issues with blue backlight. Also I stumbled upon this image, and saw that people have widely different thresholds for what they can see.

I can read roughly 70/60/40 on this image.

Anyways, while playing around with Claude I wanted something better to compare colors. So these color palettes are luminance matched to the gray background. Meaning that the eyes can't really utilize the rods to percieve the shapes.

The weirdest thing for me is that with 120deg hue (green) all the letters becomes entirely invisible, BUT it only happens at a high spatial frequency, like if I go further from the screen or zoom out. The just disappear, like an optical illusion.

So it most likely forces the use of some pathway that doesn't percieve it at all under a certain size threshold. It is also super apparant how much high gamut colors starts to glow when they are matched against a luminance matched background (like red with KSF phosphor). Obviously this is an issue, as with the oklch color space they should have been percieved as having the same brightness as the background.

Claude Artifact, Color Perception Test (no login required)

Interested in hearing what others experience while looking at the test image above, as well as the tool. Is there any clear commonalities between types of symptoms and perception issues. It would also be interesting to hear someone test it on both good and bad displays.

@DisplaysShouldNotBeTVs

async

This is actually quite interesting. Tested with my girlfriend that can see more or less the entire board at 120deg, where they simply disappear entirely for me. Also for me on the Macbook Pro M1 Max the red and pink are glowing like crazy, but for her it happens on red, cyan, and blue. To the point where she can't look at the screen. For me the cyan and blue are super pleasant with zero glow. No wonder I usually shift the screen more blue instead of red. She's rather light sensitive as well and usually gets issues from incandescent bulbs and outdoors, with strong green after images. She however loves white leds that I absolutely despise.

Sunspark

On my monitor at 120 I can see 4/5ths of the board. The rest is sliced off diagonally in the upper right.

I don't really understand this board.. I can see pretty much all of it except for the yellow at 110 where it seems to disappear, but I am not colour blind at all, I like yellow flowers etc.

I usually use 3500K for night mode (this is increment 57 on Windows Night Light).

You typo'ed here, "gets is syes" I don't completely understand, what were you saying here?

async

Sunspark the typo was that she usually gets issues. If you can see most of the board that is way beyond what I can. Does all of them disappear at 110, or just the harder ones at the right? Does it chabge if you zoom out or walk away from the screen?

I would advice to use a regular color profile and disable night shift when testing. I guess contrast adjustments on the monitor might skew things as well in some cases, of they use algorithms that adds contrast based on other things than just luminance. The test should work fine on iPhone as well.

Sunspark

Some of the ones on the right disappear yeah, but the whole panel is just very low contrast. I can see the "T"s, just they're very faded and disappear into the background. Tried my oled phone.. same thing. So what is the point of this? Just to see what colours are more distinct on a light grey background? That's always going to be black or dark blue.

async

Sunspark To build a better understanding of how monitors and people differ.

For me high gamut colors that appears to glow is a pretty big trigger. It can then also be used to adjust color profiles or even gamma color shift adjustments to reduce the effect, by for example tinting grays. The effect is pronounced when it lacks luminance contrast.

There is also the issue of reduced contrast sensitivity with many disorders and neurological issues, that obviously makes the visual cortex work way harder to pick up enough contrast while working, potentially inducing hyperexcitability. One theory I have is that dittering and almost I visible flickering keeps giving the visual cortex a clear indication that it barely percieved something important and needs to jack up the excitability. For example walking around with dry, blurry and painful eyes usually results in light sensitivity with both pain and higher percieved contrast and lightness.

I believe that the best monitor and color profile / gamma you can have is the one where you can actually read text effortlessly from the furthest away.

Not sure how common it is to percieve glowing colors, but the effect is probably hard to explain if someone never has it. Certain colors glows and pops out of the screen.

The fact that the glowing effect can vary for different colors in different people on the same screen is super interesting. Also being able to see differences in the contrast sensitivity and that different pathways takes over is interesting.

Some people have mild color blindness where one type of cone works better, and some compounds can boost or reduce the excitability of certain cones. And some can shift them, causing a smaller gap of color blindness.

Take this table with a grain of salt as it is probably wildly inaccurate from ChatGPT, but nevertheless it illustrates that targeted compounds could in theory improve specific color shifts and issues, that could be easier to test and track with a tool like this.

https://claude.site/artifacts/8e488d5c-042c-4c2f-84cc-41bbe87b2787

DisplaysShouldNotBeTVs

async believe that the best monitor and color profile / gamma you can have is the one where you can actually read text effortlessly from the furthest away.

yep, this is why I love my 2012 Lenovo yoga 1st gen so much, can read it placed on the other side of a large table without glasses (no UI scaling, 1600x900, 13 inches), or even be looking at it at a totally skewed direction or on a heavily angled surface and STILL read it perfectly and feel amazing, when almost every other screen I've tried would appear blurry and even more tiring to read in those cases