Go Gray, Not Cray: Why You Should Grayscale Your Phone | Hacker News Reader

Go Gray, Not Cray: Why You Should Grayscale Your Phone

sami.eljabali.org

81 pointssamieljabali64 comments

I tried this. One week in, I got used to grayscale as well and my screen time was back to the baseline (maybe only marginally affected). After nearly a decade of trying these tricks, hacks, and gamified interventions, it’s clear to me why they rarely work: they fixate on the symptom (screen time, social media use) rather than the underlying problem. Your mind craves to feel engaged/challenged in something. So, the actual problem is finding meaningful activities to replace your empty screen time, which isn't necessarily easy.

If you want to reduce your screen time, the boring old discipline is much more sustainable approach. Put the phone down and replace it with a book, or puzzles, or hobbies, or time with people.

I fully agree. There is no such thing as a free lunch. Social media overuse is an emotional problem, not a technical.

So, I haven't tried it yet, but grayscale was a part of my plan as well. The other part was reduced refresh rate (e.g. 4-8 Hz) to force reading-only.

Re: back to baseline. Are you sure you actually have a problem with your screen use? I feel like grayscale is mostly for people who can't stop Instagram scrolling/YouTube habits.

Disagree. "Just do it" works for some people. Not everyone.

In my experience, I hated looking at a gray screen, so I just stop using my phone when it's in grayscale.

But they didn’t say “just do it” :)

They said “spend effort ensuring other meaningful time-draws are around that are more fulfilling/less damaging”.

Relevant excerpt:

> the actual problem is finding meaningful activities to replace your empty screen time, which isn't necessarily easy.

That's true. I came off too dismissive. I like the advice, I was just disagreeing with:

> it’s clear to me why they rarely work: ...

and

> boring old discipline is much more sustainable approach

I like the idea of trying a more holistic approach, but grayscale doesn't have to contradict with that. Some people (myself included) can use grayscale as a tool alongside other things.

Agreed. My brain just adjusted to grey scale and I was scrolling just as much. There are no easy / simple hacks.

I keep on pestering folks who work at Apple to add color filters to the per-app accessibility options, who knows maybe there's someone there who'll read this. (Edit: there is an internal feature request already)

Since iOS of a couple of versions ago, you can trigger color filters on and off from shortcuts, and get a similar behaviour, but it isn't perfect and sometimes glitches. I do this so my photos app and a few others are in color, but the rest are in grey scale.

I've been in Grayscale for some time now (almost a month), and it's great. I always wanted to have a phone with an eInk display, and this is pretty close feeling (aesthetically).

Scrolling is no longer interesting, and food looks un-appetizing. Making the digital reality look boring is a good deal to make the real world look more exciting.

Thanks to comments from @jtbaker and @SkyPuncher I just added a shortcut to the "pull out" menu so I can now turn off when I need to work with pictures where colors are important.

My theory is, that people who have the discipline to follow these weird self-imposed restrictions, don't actually need them.

They can just follow through with the self-imposed restrictions on the actual problem.

If you want to limit social media time, then limit your social media time. Can't? BW screen won't help you.

Many people who can make a change, still benefit by using a change in context to help them mindfully break their old pattern.

Cues are powerful tools.

I was thinking to do that for my kid's phone.

I tried it for a while, it was fun explaining it to people, but didn’t actually help much. I ended up blocking all time wasters except HN, which is almost monochrome anyway.

I set grayscale in my phone's quiet hours settings. It's to help me sleep, rather than to reduce my phone usage. It means if I wake in the night and look at my phone, I'm not blasted by colors. Or if I stay up a bit later than usual. I find it beneficial although probably not revolutionary.

I did try setting my phone to grayscale during the day but didn't see much if any benefits there.

This was my experience as well. While it is less straining on the eyes, that was the only benefit I saw. I didn't see a reduction in screen time or less anxiety about notifications.

I actually just recently bought a big me hibreak pro phone. Eink, supports Google Play natively, (I can still install Instagram, Google maps, Facebook, and WhatsApp, etc). Which were my two biggest needs.

It has been pretty great to use. The whole paradigm changes, because it also has the slow refresh, and the screen is physically different, single level brightness.

Funnily enough, I now catch myself with increased short term anxiety and FOMO. I've just acknowledged it as withdrawal syndrome from the dopamine of short form videos. That and I misplace the phone a bit more now because it's no longer a crack pipe.

It's taking effort to stick with it, but I increasingly love it. And I still get to partake in "society" and social media, just on my own terms.

You also realise just how many ads there are, because they don't draw you in so you can see them more critically. What I thought was one in 20, is actually something more like one in 4

What about a feature that randomized the app locations on your home screen every time you open it? That way, no muscle memory develops.

Did something like this and just got comfortable always using app search instead of icon selection

Foiled again!

I just tried this and found having Enhanced Contrast with grayscale looks a little better. I dont do doom scrolling on social media, but if this increase my phone battery life by 50% I will be happy. Since most of my days is endless Whatsapp or Email.

I am also wondering if simply having the filter showing in between colour and grayscale would improve battery life as well?

This is such an interesting idea. Might as well try it

Edit: didn't last long (about an hour). Needed to show some one a photo and had to turn it off.

I was able to add it as a "Color Filters" "quick control" toggle from the top right drag-down menu (not sure what you call that) in iOS 17. We'll see how long I last with it. I'm intrigued as well.

that menu is control center

I keep it in my control panel so I can flip it on and off easily

I ser the Accessibility Shortcut to Color Filter. A triple press of the button toggle the filter.

This ideas pops up pretty often, and people have their opinions. Personally, I suggest against this, especially if you are older (40+ years).

I’ve tried this, and it is a hindrance to some of the critical apps I use regularly, such as Camera, Maps, Messages, and occasionally the Phone App.[1] Of course, you can set shortcuts in the Control Center, double-tap the back of your phone, and all of that jazz, but it is slower, and the UX is a hindrance when you need it.

Instead, have the minimal App on your HomeScreen to avoid distractions as much as possible and/or remove the usual suspects — Social Media Apps, Games, etc. The idea is to make your Phone boring but just works when you need it. You can continue to use them on your desktop/laptop, which prevents that easy reach when you are not at your desk. Read[2] or write[3] if you are serious about avoiding distractions. If you already use a Smartwatch,[4] you can reduce your phone usage a lot more.

And the eyes work much harder in the Grayscale than in well-contrast colors. I prefer most things minimal; no labels, no text where not needed, learn shortcuts, etc. However, my phone is set to show labels and has higher contrast in the evening/night, while it shows no labels during the day. If I have to glance at it at night while driving or wake up to VIP/critical calls at night, I can see way faster and easier than squinting my eyes or fumbling for the glass. Grayscale is horribly in this situation.

And shooting photos in Grayscale, even if the actual photos are in color, is another blunder. I want to see the shades while shooting to compensate for any errors. Again, especially in the dark (however good phone AIs have become), it will always be either too bright and saturated (compensated by the AI) or too dark with a chance in lens at the last moment, trying to focus elsewhere.

1. https://brajeshwar.com/2024/phone/

2. https://brajeshwar.com/books/

3. https://brajeshwar.com/2025/notes/

4. https://brajeshwar.com/2024/watch-tiny-handy-computer/

Works great with iOS's double/triple tap on the back feature.

TIL! I had no idea this was a thing. https://support.apple.com/en-us/111772

It really is a great fit for this feature.

I prefer using the same feature to have an extremely warm (almost red) tone. I think it's much more pleasing than b/w and results in less blue light for me.

I do similarly. Triple tap puts it in night mode, red and black. It’s nice for checking messages in the middle of the night.

As someone that grew up without mobile phones and Internet, not being able to disconnect seems rather strange.

Maybe the memes about growing up in the 70 and 80s have some truthiness to them.

"Psychology of people thar grew up in the 80s"

https://youtu.be/8VADi7dPb44?si=L0BtbQoSe0-BuSAh

Didn't work for me. App blocker from 9:30 PM - 5 PM. 30 mins Max a day of short form content apps.

I just installed Foqos[0] (iOS, free) for this exact purpose. Excellent app. You can require scanning an NFC tag or QR code to disable app/web blocking.

I plan to put an NFC tag in my car, so that (while I’m home or working at my desk) I have to physically go outside if I really want to unlock my blocked apps before the end of the preset schedule. Meaning…. in reality…. I’m not likely to.

[0] https://www.foqos.app

Vibrant colors of my OLED phone screen and snappiness of 165Hz refresh are recurring source of delight in my life. I won't rid myself of it.

Some time ago I bought myself eink tablet to try something new and my disappointed with its screen was severe.

Decades ago I had one or two tẽte à tẽte about grayscale not being the same as black and white. You could emulate grayscale with b&w if you had a much larger canvas. In short: Black and white is 2 bits, grayscale is 8, 16 , more? bits

Am I wrong?

You're not wrong, Walter.

https://www.youtube.com/watch?v=C6BYzLIqKB8

You are correct, grayscale is where every pixel's R = G = B, which for a 24 bit image would include 256 colors.

Black and white is 1-bit, where one value (say, 1) means white and the other (say, 0) means black.

You know avoiding the pain, struggle and pseudo-science of gray pixels… you could just turn every notification off and remove any social media. Call me crazy, but I reckon this will go a lot further than any monochromatic color scheme in achieving the desired results.

I tried everything under the sun including the grayscale trick, and at the end of the day there were three things that worked. Putting the phone on silent, putting it out of sight, and simply turning it off.

This resulted in 5 hours of phone time per day declining to 1 (it's my companion at the gym plus during most meals and that's OK).

Everyone's approach is going to be a little different depending on the rhythm of their life. For me the phone usually stays turned off for most of the morning now. It's in a drawer for most of the afternoon/evening. If I'm out and about it's in my pocket or bag on silent. It briefly gets unmuted at times when I'm expecting a delivery, appointment etc. and that's about it. The bar is high because the peace of mind is too great to lose.

FIVE hours a day? I spend one hour a day and I feel like I'm constantly battling addiction.

> Color pixels drain more energy than grayscale ones. Personally found my phone lasting twice as long as before. Over time, a considerable extension of your phone’s lifespan.

What? Why? Why would you even entertain that as a hypothesis?

They said they found themselves using their phone far less due to the grayscale, which would be the real thing extending battery life here. Or at least, this was what I assumed on reading.

That is likely. Another factor that came into my mind is the gpu using less power due to simpler computations. You can store less data for grayscale, so you need to go over less pixel data to do effects etc. Whether accessibility controls achieve this or not would be implementation dependent I guess.

Even with the best GPU optimizations, most of the data will be processed in full color and then tossed through an extra pass at the end. More likely is that all the data does that.

Yeah, that’s the only explanation that makes sense. It’s just so strange to think that color pixels would use more energy.

I guess if one color pixel was significantly less efficient, and that color was also overrepresented on the display, then MAYBE changing to grayscale would require slightly less power to display the same intensity. But I don’t think that convoluted scenario probably isn’t what this person was thinking.

Why is it strange? Given that you have no idea whatsoever how pixels work, whats strange is that you have any expectation at all.

What? I think we all have some idea of how pixels work.

I questioned the same thing over a decade ago with my then-shiny Samsung Galaxy S5: At the lowest of its low-power battery-saving modes, it drained the color from the screen and made it greyscale.

Perhaps it can make sense for LCDs: After all, LCDs operate by blocking backlight.

Blocking less backlight (by area) by using greyscale might make sense: It seems obvious that a higher perceived brightness can be achieved for any given pixel if using greyscale instead of using colors, just because less of the backlight's area is occluded.

And then: Usability can be maintained while also reducing backlight intensity.

Reduced backlight intensity definitely does have a big effect on battery life.

So -- for LCDs -- it might make sense.

(But even if it makes sense for LCD, the S5 happened to use one OLED variation or another, not LCD. Perhaps there's a non-linear relationship between subpixel brightness and power consumption, and keeping 3 subpixels (RGB) barely-illuminated is more efficient than keeping 1 subpixel (G, say) more-illuminated is?

Or, what I determined to be most-likely at that time: Samsung was simply an uncoordinated wreck that was full of shit.)

> It seems obvious that a higher perceived brightness can be achieved for any given pixel if using greyscale instead of using colors, just because less of the backlight's area is occluded.

When converting to grayscale, you typically calculate the value of the pixel and then set all color components to that value. The point of this is to keep the luminance the same as it was in the original color pixel. If you’re doing this correctly, the perceived brightness stays the same.

And just as a smell test: have you ever converted an image to grayscale and flinched away because it seemed twice as bright? Of course not; it just loses its color.

The only way you would get more perceived brightness at lower backlight intensity would be if you physically removed the color gels that overlay the LCD matrix. Which is obviously not what they’ve done here.

I’m pretty sure the increase in battery life they observed is simply because they’re using their phone less, which is very much the main upshot of the other benefits they listed. The idea that color pixels drain more energy is just obviously nonsense.

> When converting to grayscale, you typically calculate the value of the pixel and then set all color components to that value. The point of this is to keep the luminance the same as it was in the original color pixel. If you’re doing this correctly, the perceived brightness stays the same.

This is precisely wrong.

To maintain perceived brightness, you want to set the color channels to the original value weighted by a scale factor that accounts for the eyes’ sensitivity to each color channel.

Fine, luma, not luminance. But what you're describing is exactly that calculation. This does not change my point. Again: If you’re doing this correctly, the perceived brightness stays the same.

> And just as a smell test: have you ever converted an image to grayscale and flinched away because it seemed twice as bright? Of course not; it just loses its color.

Of course that is the way it is normally done. But it does not have to be done that way; does it?

Guidelines and norms are meant to be bent.

To demonstrate: I may be old, but I've definitely owned monochromatic "paper white" VGA displays that only responded to one channel of RGB and ignored the remaining two; the other two pins weren't even present in the connector. (These were trash for displaying color images without special care in software-world, but they were cheap.)

> The only way you would get more perceived brightness at lower backlight intensity would be if you physically removed the color gels that overlay the LCD matrix. Which is obviously not what they’ve done here.

We can evaluate that.

Suppose we have one ideal backlit pixel displaying FF0000, and that to achieve FF0000 66.6% of the backlight's total output for that pixel are being blocked and only the remaining 33.3% gets transmitted. Two subpixels are occluded; one subpixel allows transmission.

Suppose that with a backlight intensity of 100%, this pixel has a luminous output of 1 unit. (1 of what unit, you ask? For our purposes, it doesn't matter -- it's just 1 unit.)

Now, suppose we double the area of exposed backlight by instructing our pixel to display FFFF00. Our backlight intensity remains 100%, but we have twice as many subpixels allowing that backlight to be transmitted. The backlight stays the same, but our measured luminous output for this pixel is now 2 units.

To continue: FFFFFF. All 3 subpixels allow light transmission. Our luminous output is now 3 units for the same level of backlight.

Thus: With this result of 3 units, we've got 3 times as much light as we had at the beginning -- for the same pixel, with the same backlight, and about the same energy use.

---

To get back to the same 1 unit luminous intensity as we had with FF0000 @ 100% backlight, we can run the backlight at 33.3% for FFFFFF. This saves power.

Our pixel is producing 1 unit of luminosity with FFFFFF, but with only one third of the backlight required to display FF0000 with 1 unit of output.

> The idea that color pixels drain more energy is just obviously nonsense.

That's not obvious to me at all for a backlit LCD.

FFFFFF is always going to be brighter than colors like FF0000, 00FF00 and 0000FF are for a given backlight intensity, which permits the opportunity to reduce the amount of backlight provided, use less energy, and still provide the same luminosity as a color would.

And it accomplishes this without stripping layers out of an LCD panel, or using magical thinking.

Is that what was proposed? Fucked if I know. I find that articles like this (and approximately anything else that has ever been published with the words "you" and "should" juxtaposed in the title) are meant to make people bicker about dumb shit, and I try to avoid poisoning my brain by reading them.

So specifically on a backlit LCD screen with dimming zones, and in the specific case where an entire zone would have originally been blue or red (which are perceptually dimmer), you could plausibly get a small amount of energy savings. But “twice the battery life” from this is not plausible.

Specifically backlit LCDs. Maybe with dynamic backlight; maybe even with zoned dynamic backlight -- but definitely backlit LCDs. It only works in corner cases where important information would normally be displayed as bright saturated subpixels (colors), and even then it only really gets good with special dynamic processing (which probably doesn't exist).

So in terms of practicality: It has none.

And at best, all that these hypotheticals can do is stretch out a battery a little longer by reducing the intensity of backlight that is necessary in order to succeed at using the device in a given level of ambient light.

It has never been my intent to demonstrate "twice the battery life" ["with this one simple trick!"]. That's the path of nonsense, and of chemtrails. :)

Just learned you don’t have to go full grayscale! You can put the filter on 80% and still get the color semantics while also being less stimulated

Thanks to whoever added this

I have color filters set to kick in if I double tap the back of iphone it shuts off everything but red subpixels. Good for preserving night vision.

On android this is easy you can add a button to the bottom nav bar

«Color pixels drain more energy than grayscale ones. Personally found my phone lasting twice as long as before.»

Is this a joke? Is there a real physical effect at play?

I can't imagine. AFAIK no phone has "grayscale" pixels. Grey or white light is achieved by blending the other colors equally.

A true monochrome screen is a thing, but they are for specialized applications and not used in phones.

Maybe power draw is not linear and with grayscale rgb sub-pixels can operate at lower intensity and lower power draw than if the luminance wasn't distributed across all colors?

They said they noticed themselves looking at their phone far less. Most likely this is what saved the power, just a typical spurious correlation and a bad theory for the reason.

some oled displays have white subpixels, i dont know if the power cost is a thing though

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