There is. You can listen to media query changes. So listening to prefers-color-scheme already works quite nicely and I use it in my current project.
Browsers should implement setting the preferred scheme per site at some point.
It would also be interesting if they could support more than just light and dark.
Boy I really hope so. As it stands a lot of people implement their own toggles and only use „prefers-color-scheme“ for the initial setting of the theme. Using the plain media query everywhere would be much preferable and actually reduce the amount of CSS needed by a fair amount.
oh neat. I'll have to see if it propagates to iframes, if so I can update FastComments since it supports dark mode.