I've not upgraded to windows 10. Not sure I want to at the moment, am happy enough on 7. I've set a reminded for 11 months from launch giving one month then to decide or not to take the free upgrade.
I was thinking more an option for a dark theme at the bottom left of the main forum page, like you get with the Elite forums. And once your logged in it remembers your choice. I use the 'Elite tempered' dark and orange' theme on there.
or for example the dark theme option on Discord. Various levels of dark to mid greys, perfect for my eyes.