This thread is no longer relevant, since BLF switched from Drupal to Discourse. The new Discourse version of this thread is here:
Additionally, the themes are (mostly) available directly on the server, so people don’t have to install a browser extension to use them. Just pick a theme from the theme chooser widget in the sidebar, or in your user preferences.
I find black text on a white background hurts my eyes, and I spend a lot of time on BLF, so I made a dark theme.
Er, actually I found a dark theme in the userstyles.org repository a while back. And I modified it a bit. Then BLF got a major upgrade and the theme broke, so I fixed it and modified it quite a bit more. I figure I should share it in case anyone else prefers dark themes.
The theme isn’t 100% complete, and I don’t know much CSS, and I’m not good at graphic design, but it mostly works…
Patches, enhancements, and bug reports are welcome.
To use this, install the “Stylus” extension, then search the userstyles.org repository for “BLF” and follow the instructions there. (Update 2018-07: Use Stylus, not Stylish… Stylish was bought and became spyware)
Here are some screenshots of how it looks. I’ve set them to scale down to fit the screen, but if you click them it’ll show full-size: