>>I was a huge fan of using f.lux on my computer to adjust the color settings to be easier on my eyes. But these days, both Windows and Mac offer native dark modes to change the color of all settings screens, and system functions.

f.lux is still much more flexible than the Windows native "night time" mode, including custom color balance and disabling for specific apps. (undisturbed color balance is important for photo/video editing on calibrated monitors)

That said, yeah, I use dark/night theme on everything - and still remember the old P39 phosphor tubes fondly (absolutely no flicker as the phosphor stayed lit for longer than the rescan interval, made for a bit of smearing when paging up or down, but IMO a good compromise).

System-wide night mode (including f.lux) is more about removing the colors that trigger the light sensors in the ganglia connecting rods and cones in our retinas. These sensors appear go be an evolutionary holdover apparently going all the way back to the development of vision, and are connected to a more primitive part of our brains - which is why light that those sensors detect affects our circadian rhythm.

Dark mode/theme is more about not blasting our eyes with light - and, for me, at least, it seems to help with readability (but, hey, I transitioned from reviewing code on-paper to on-screen back in the P39 era (late 80s).