Hello,
I'm sure most of you are aware that there's websites that have a button to quickly switch between a light or dark theme on their website (such as YouTube) or even a night mode that increases the red colors to aid in not confusing the sleep cycle (this is on phones primarily nowadays).
I think it would be super great if a future feature could make this possible. It would also be more easily accessible and it is modern, so most people should already be aware of this than the really old school method.
I think a lot of users don't like seeing a dark theme by default (like my site), but it's more fitting to the subject matter. There's people that also prefer not to be blinded by a brightly lit screen when they're viewing something at night...