We now have a dark theme for the forums! 
Go to preferences and select your theme there:
Preview:
We also have the Dracula Theme as it’s a personal favourite 
8 Likes
Finally, I’ve been waiting for this!
Everything is really large on Dracula for some reason. Dark theme looks great though!
You can simply just change the text size to small.
I like it the most on the “Dark Theme” small, “Dracula” makes small look more like medium/large lol. In other words, I can’t make it any smaller.
I’ve just pulled the theme from the site and tweaked a few colours