Hello,
I, as a fan of dark themes, would love to be able to choose between the current and a dark theme.
I do know that the Sponge devs have a lot to do, but we still have a big and experienced community, which could create (or vote for) a custom dark theme to be available as an official theme.
There is already one community-created design that needs client-side extensions to work, though.
I’d like to as well, although I’m not sure if Discourse supports theme switching per-user. Probably does, but I can only guess. On the other hand, I think @octoshrimpy is still working on that theme. They may already plan to implement it when it’s more polished.
So far that is the plan, but I’d have to ping @riking for more info on that.
Also check this one I’ve been working on. Still being polished, but is more Discourse-friendly.
I would like that a lot.
When I’m having a headache I can’t look into bright colors because that makes it worse, so I put everything on the lowest brightness, I even use screen dimmer on the phone, and an extension called “High Contrast” that reverses the website colors.
Sponge’s forums are too bright 
High Contrast:
High Contrast doesn’t work properly on recent flat designs I guess
