Windows Upgrade Help and more

Agreed. Another option is to temporarily disconnect any non-essential peripherals, like extra monitors or printers, as they can sometimes interfere with the upgrade process.

Same here. You could also try a third-party app like Winaero Tweaker to force a true black theme. Another option is checking if your display has a specific OLED care or deep black setting in its own menu. Let me know if that works.