I've updated my dropbox CSS links for Opera/Chrome etc and Firefox.
Better than Stylish is Stylus
Here's one for Chrome/Opera/Vivaldi, and now Firefox - by a new dev dissatisfied with the current stylish add-on's new wide ranging permissions and data mining.
The Github link: https://github.com/schomery/stylish-chrome
A dark style for the Stylus add-on manage and settings windows. Created by someone involved with Stylus.
Or search other dark styles for Stylus:
Save your eyes from bright screens with the dark forum theme.
Also some extra info below for Opera/Chrome (which I use), and Mozilla Firefox version of the Stylish add-on CSS.
Opera / Chrome Stylish add-on CSS - link (v004b).css
Click to create a new Stylish entry and copy and paste the CSS from the link above into the page and name it and then save.
Then in the stylish add-on manage page for this new style (opera/chrome).
Add these below using the option 'urls starting with':
Maybe for you using the * wild card will work at the end of just a couple of URls... for me it didn't for some reason and some forum pages like badges, bio profile etc would revert to forum default white. So I added these urls above.
The FF stylish add-on CSS below already has these URL's included in the CSS. And you create it the same way by adding a new styilish entry.
Mozilla Firefox Stylish add-on CSS - link (v004b.css)
Open on windows with wordpad to edit outside of stylish - or your preferred CSS editor. Let me know if the links don't work. Scanned CSS files with anti-virus program before uploading them. If you right click and 'save as', please scan them yourself before use. Otherwise just open the link in a tab and copy the CSS direct into a new Stylish Add-on style page for both Opera/Chrome or FF.
It would be really good if we could have an installed Discouse dark and or semi-dark theme to choose from at some point in the future. Not to detract dev time from game development though, as and when @INovaeKeith