[Readerium]

No AMOLED screens on pure black do not consume significantly less power than a dark non pure black color.

The power consumption on pure black vs another dark color is extremely similar. This is because on AMOLED screens individual pixels control themselves and power for off vs dark is very similar.

Source: https://www.xda-developers.com/amoled-black-vs-gray-dark-mod...

[Miraste]

Not all dark modes are really that dark, though. MacOS comes to mind but there are plenty of examples. I'd be interested to see a comparison of average luminance.

Also, gray uniformity is an unfortunate shortcoming on a lot of OLEDs.