Hunter20 It's not actually white, notice how if you mess with turning off the brightness compensation property it will switch from a yellow white to a reddish white implying that the yellowish white you were just seeing was not actually true white. Who knows if the reddish one is true either…
One of the reasons why they do this is probably relating to something that I observed on an earlier 2016 Intel MacBook Pro: in Boot Camp Windows, where there is much less color calibration going on, I noticed that when turning the brightness up and down the screen will alternate around every 10% between a bluish white and a yellowish white. Probably as a side effect of however the hardware backlight works. I've also noticed a similar thing to a milder amount on Asahi Linux on M1 Air. Yet while booted into macOS on either Mac, this "doesn't happen".
So, to "compensate" for this variance in color accuracy, I've noticed while booted into macOS, even on (some) Intel Macs in addition to M1 ones, the white is changing very slightly (which essentially needs flicker to achieve in such a subtle amount) to prevent it from "becoming inaccurate" and looking more similar at all brightness levels… and then causing tons of strain from doing so
In addition to this brightness compensation there's probably tons of other post processing layers we don't know about that are ALSO affecting the white even further
(to be clear, this is in regards to the internal display, most of this doesn't happen with external monitors. Stillcolor seems to actually fix external monitor issues for me entirely, the remaining problem in my case though is that all of the external monitors I own have their own internal FRC when provided an 8 bit signal even with a totally clean source like an old PC, and that's still a big issue for me.)
So yes, you're actually semi correct in that "it's a special white that only Apple displays can provide".
Also, to make matters worse, Apple will still dither even if they switch to true 10 bit internal displays in the future, because they actually made any Mac that supports Display P3 use a 16 bit color space on the GPU. I'll make another post soon about this. They mentioned / confirmed this detail in the WWDC 2017 talk about introducing Display P3.
Finally, about the "black text" part - remember that (unless you're using a retro pixelated style font that is perfectly aligned to the grid) all the edges and curves of black text are actually made up of shades of gray and will thus flicker on any temporally dithered display.
P.S. a quote from a blog post when Apple introduced EDR:
https://prolost.com/blog/edr
Apple has remapped “white” to something less than 255-255-255, leaving headroom for HDR values, should they be called for. The operating system is complicit in this trickery, so the Digital Color Meter eyedropper shows “white” as 255, as do screenshots.
With Catalina, Apple quietly changed what “white” means for millions of Macs, and none of us noticed.
Between high-bit-depth P3 displays, display color management, software calibration, and True Tone, it’s probably been a very long time since “white” in a Mac UI was truly 255-255-255.
So yes, you're actually semi correct in that "it's a special white that only Apple displays can provide".
Also, to make matters worse, Apple will still dither even if they switch to true 10 bit internal displays in the future, because they actually made any Mac that supports Display P3 use a 16 bit color space on the GPU. I'll make another post soon about this. They mentioned / confirmed this detail in the WWDC 2017 talk about introducing Display P3.
Finally, about the "black text" part - remember that (unless you're using a retro pixelated style font that is perfectly aligned to the grid) all the edges and curves of black text are actually made up of shades of gray and will thus flicker on any temporally dithered display.
P.S. a quote from a blog post when Apple introduced EDR:
https://prolost.com/blog/edr
Apple has remapped “white” to something less than 255-255-255, leaving headroom for HDR values, should they be called for. The operating system is complicit in this trickery, so the Digital Color Meter eyedropper shows “white” as 255, as do screenshots.
With Catalina, Apple quietly changed what “white” means for millions of Macs, and none of us noticed.
Between high-bit-depth P3 displays, display color management, software calibration, and True Tone, it’s probably been a very long time since “white” in a Mac UI was truly 255-255-255.
Due to all of this I have given up on "strain-free MacBooks / iMacs / iPads / iPhones / Apple Watches" at this point.
Using a Mac as a desktop with Stillcolor and a safe true 8-bit zero FRC external monitor is the only way to fully salvage Apple technology
(aside from hacks like streaming macOS through remote desktop to an old Windows laptop, which is my main and only strain-free setup at the moment. If you're wondering why I'm not using an external monitor myself it's because personally I don't want to spend time getting external monitors working as I have ergonomic issues using desktops anyway, I strongly prefer laptops and the ability to not have to sit in one place all day.)
My goal is to fully switch my portable workflow over to Windows and Android this year, because, even though there are still many bad devices there, at least I have options such as different brands to choose from and easier ways to fully swap the LCD inside of a laptop