Where to Find the Colors Your Screen Can't Show You

While it is true that some saturated blue-green colors will never be reproducible with only 3 primary colors, the CIE 1931 chromaticity diagram used in TFA overemphasizes their importance, because human vision cannot distinguish many colors in that area of the diagram.

In reality, the greatest defect of the sRGB color space, which is still too frequently the default color space, is that it is not able to reproduce many saturated orange/red/purple colors, which are very frequently encountered around us, e.g. in flowers, fruits and clothes.

The missing orange-red-purple corner appears small in the diagram in comparison with the missing blue-green corner, but in reality humans perceive much more different colors in the orange/red/purple corner, so the relation between those areas would be opposite in a uniform color space.

The Display P3 color space is much better than sRGB for reproducing orange/red/purple colors and now it is available even in many cheap monitors. However many monitors that can reproduce Display P3 come configured by default to use just sRGB. Such monitors should always be reconfigured to use Display P3.

Monitors that can reproduce an even greater part of the Rec. 2020 color space are obviously better than those that can do only Display P3, but such monitors with a higher color gamut are usually more expensive. The full Rec. 2020 color space can be reproduced only with laser projectors, because it uses monochromatic primary colors.

I took up acrylics painting a few years back and I've been surprised by how much is lost in photos and videos. The two colors with which I've noticed this the most are ultramarine blue and prussian blue. I don't think it's just the color though, part of it comes down to how light is reflected off the painting and where you're standing, as well as the texture and the brush strokes. I have a few paintings hanging in my room and occasionally I'll look at them for a while and it'll reveal a new perspective to me that I had previously missed, despite being the one who made it.

This post is making me feel a bit inspired to go outside and immerse myself in the forest to take in the greens. Thanks for sharing.

What I missed in the article: the curves of the three “cone kinds” overlap. What if you could stimulate kinds of cones individually to see entirely new colors? Some people shoot layers at them into eyes. But you can also try this website: https://dynomight.net/colors/ (previously on HN but search fails me).

The phosphor screen of a B&O MX8000 TV (a Philips tube) was unlike any I’ve ever seen in terms of cyan intensity. That was in 2020 while the tv is from the 1980’s. Playing Donkey Kong on it was totally different than any other screen. It was like a Morpho butterfly, but in the article it is pointed out that phosphor screens have limited color range.

Triangles between screens may differ with tuning, but I suppose they all are limited in range. I’ve yet to experiment if this experience was a “brand experience” because I liked the TV or that the colors are indeed more intense than even some HDR/DV flat screen from the past few years.

This article was so well written that it gives a lot of energy to make this comparison for real. Absolutely masterful writing and all of the plenty examples make me want to look for colors I’ve missed out on while watching so many screens.

What the article does very well is vibrantly describe what you are missing and then post an image of it, such as a beach. Looking at that image, it falls absolutely flat compared to memories and the imagination of those places. This makes it tangible how limited screens really are.

Edit: added last paragraph

Really nice article, I'll look closer to green lights next time I see one.

The most striking experience I had was working with a blue laser (430nm). The best way I found to describe its color is that it was screaming "blue" at me. Since then, I'm always disappointed when looking at a screen displaying #0000FF.

Really enjoyed the article, even though it's not a new topic to me, but still it was very interesting, very nicely written and I still managed to pick up a couple of new details.

To be fair to Jurassic Park, though, at least in the book the quirks of T-Rex's vision were explained by the details of genetic engineering (the base DNA used was some kind of amphibian, that allegedly had this problem — still not very scientifically plausible, but not quite as silly as in the movie). It goes a long way to emphasize that in the end these are not real dinosaurs, these are human-made abominations.

Off topic, but the other articles are well made too. I enjoyed this one: https://moultano.wordpress.com/2025/02/24/you-should-make-cr...

Incredible article. I used to work as a light designer and therefore spent lot of time thinking about colors and training my eyes to see them more precisely. I lost some of this competency surprisingly quickly, but this article brought many great feelings/souvenirs back.

Thanks to the author

That was incredibly well-explained. Kudos.

I do have a question that the article doesn't seem to attempt to answer, though. The article says (paraphrased in my new understanding) that any spectra which makes the cones in your eyes react the same way will result in seeing the same colour. Do we know of any examples of this?

(Colour-blindness seems like an obvious example; I'm curious though if there are any examples of two common scenarios where it can be demonstrated that there are different spectra in each, and yet most people will see them as the same colour.)

> Today, on your way home, look at the “green” light on a traffic signal. It’s not green.

Independently from this, the names for colors are culturally determined.

The Japanese call green traffic lights as 青 "ao", blue.

Russians have different terms for different shades of blue.

ACES AP0 is the only color space I know that is designed to represent all possible visible colors. It's a purely theoretical color space, though. The widest color space designed for actual implementation, Rec. 2020, still can't faithfully show most of the natural greens and cyans, like your green laser pointer.

My debatable factoid is that all vision is movement-dependent, including human vision, and so the bigness and wonderfulness of the tyrannosaur's eyes is beside the point of whether it needed its prey to move around in order to perceive it.

https://en.wikipedia.org/wiki/Stabilized_images , https://en.wikipedia.org/wiki/Fixation_(visual) , https://en.wikipedia.org/wiki/Microsaccade

We fake the movement of anything we're staring at, by means of tiny automatic eye movements, in order to remain able to see the thing at all.

What an truly incredible article, particularly the way the color space diagrams are used to gradually tell the story (and the prose is great too). I actually want to read it again tomorrow morning in more depth.

Such a cool article chock-full of cool facts!

> Nearly every species of scorpion intensely fluoresces under UV light. […] Scorpions have photoreceptors in their tails, separate from their eyes. […] It is hypothesized that a scorpion uses this fluorescence to tell whether any bit of its body is left exposed from its hiding place. Its tail “looks” down at its body, and if it sees its own fluorescence, it knows it is exposed to light, and in danger.

And a special call-out to the “Andean Cock-on-a-Rock” :), see a photo in the article.

Colors on the screen are like symbols. Like words. they aren't the actual experience. They evoke the experience. Your mind connects the color to a memory and then it's the memory that you experience.

That's screen reality. 1% evocative symbols and 99% in your head.

Great article. Small nitpick though: while I understand that P3 deserves specific mention because it’s so ubiquitous now, it’s not like Apple invented the idea of wide-gamut displays. Adobe RGB, commonly used by wide-gamut computer monitors, in particular is noteworthy in the context of this article because it extends further into the blue-cyan-green than P3,

Its unclear to me why the color space is 2-dimensional. Why wouldn't it be a 3-dimensional space, indexed by how much each of the 3-cones is activated ? Not clear to me from the article!

I'm having an amazing time seeing colors now because I just had cataract surgery on my right eye (left eye next month) and have a clear lens again. If I compare my new right eye to my old left eye, I'm seeing colors I haven't seen in decades. Skies look blue with my right eye, gray with my left.

It's odd he noted Apple monitiers were "better". Maybe but marginally. Many options for other platforms, like Asus Pro Arte, beat it handily. And profressional color graders use Sony BVM series (Trimaster HX / OLED) for HDR or Flanders Scientific (FSI) DM/XM series or Eizo ColorEdge CG series. You won't see a single Mac at a movie studio for movie editing or color grading.

My two most favorite and most seldomly seen colors are near uv. One of them is a blue sky at an altitude of over 3000m. The other was a powerful deep blue laser in a microscopy lab, just on the end of the visible spectrum

"The eyespots on a peacock’s train are super cyan, so when the peacock spreads its train feathers it is going super saiyan super cyan." Haha.

Very well-written!

I wonder if the inaccurate representation of colors by screens, etc, in any way underlies the distinctive color palette of many AI image generators?

Somewhat related, but TIL the macOS Screenshot.app utility (and the system wide keyboard shortcuts) in Sonoma got HDR capability to help re-convey just a bit more fidelity. Even in PNG, it keeps the display profile, just not HDR.

Open Utilities->Screenshot.app Options->Capture/Capture Format->HEIC. Note, it changes the system screenshot default away from PNG too.

Very well written, super interesting topic. I never understood all these natural reasons why real life colors feel so much more vivid. I guess when I look outside of the rgb triangle in the graphic, the cyans/blues/greens shown (since I'm seeing this on a screen) are sort of shadow colors? Approximations without the full vibrancy?

I can tell you there are some places people do notice that a screen can't reproduce all the colors they can see.

Anyone who has mixed paint at hardware store or paint store with a modern paint machine will eventually notice this. A of lot them have a spectrometer to match color from a sample. The software often has a preview that appears on a screen of the sample color. That preview color is often not quite the same and it's often either the limit of the sRGB color space or the monitor.

The data from the spectrometers is eventually converted to CIELAB color points with a D65 white point. Then that little preview needs to be converted to sRGB to display it or some colorspace the system supports.

There also some problems with the LAB colorspace, but they are minuet compared tot the limits of sRGB and display hardware.

If we had a display with n (n>3) pixel colours, say (red, green, cyan, blue) for example, we could display more of the colour space. Shopping list: 4 colour channel display, 4 channel GPU, 4 channel software. Why isn't this a thing already?

This reminds me of a video [1] going over the use of structural color photography, where theoretically what you see in real life is what you get in your final image. It cover some of the same topics, but goes more in depth about the process of structural color and some animal examples, like the butterfly mentioned in the article. If you have an interest in chemistry or film photography it is a great watch! This process was also, to my knowledge, the stepping stone for holograms, which we can now see structural colors everyday on IDs and licenses.

[1] (18 minutes) https://youtu.be/-DyrBDsKA5s

Can these colours be replicated or captured using ink, paint or traditional film photography?

Reading this made me realize how much of my day is spent looking at screens. It's weird to think there are colors in the world that I've technically seen before, but have never actually been able to capture or reproduce digitally.

I once abseiled into a crevasse while in Antarctica. The colours I saw in there were utterly breathtaking and I never knew why. Now I do, and this also tells mewhy the photos don't even remotely do it justice (aside from not being as big and three dimensional!)

Thanks for such a beautiful article about not looking at a screen: I'm off outside... :)

Impressionist paintings used a lot of synthetic ultramarine, they look very different IRL. There is a whole room in the Orsay museum where paintings seem to glow from the inside in the dark.

Many modern triple-laser projectors can reproduce or exceed the Rec. 2020 color space. It's still not full coverage but much larger than P3.

A lot of this comes across similar to describing how the upper range of human hearing is 27khz, not 20khz and commonly believed, and where to hear these.

Hint: If you listen to a live orchestra without amplification, and the sound "sparkles", it's because of the frequencies slightly above 20khz that are normally filtered out of audio CDs and streaming music.

Great article! After reading I started to think there must be some purchable items which would demonstrate colours outside P3 colorspace. It would be cool to hold one on your hand and experience how a photo of it just cannot do justice.

Anybody know any links to webshops for such items?

interesting, nicely written article. if you want to replicate the colors, you can use wider gamut end to end:

- use raw format on the camera

- edit raw eg pro photo rgb

- send this to a wide gamut printer with a large set of inks to view the image

the printer would replicate the color outside the srgb space

there are such inks as cyan, light cyan, orange

My favorite color in all the world is the green of a mineral called dioptase. It's a deep, dark green, richer than an emerald. It looks amazing in real life and utterly boring on an RGB display. The Houston Museum of Natural Science has a large sample; every time I'm there I go stare at it for a while.

When reading the article, 520nm light is closest in color reproduction to the "yellowgreen" Crayola color, as seen within their 64-pack.

Can't this be fixed by adding a cyan to RGB, making RGcB? Or, even adding yellow and magenta for RyGcBm?

I hate that type of diagrams. Why sRGB-encoded image, pretends to show any color outside of sRGB region? It doesn't make any sense! (and when these diagrams attempt to illustrate sRGB, often actual colors encoded are narrower than full sRGB)

Can you see them with film? Either projected or on photographic paper.

what a beautiful article, thoroughly enjoyed reading it.