Rated 5 out of 5 stars
This does a really good job of replacing the stock bookmark options of firefox. Navigating to bookmark folders is a breeze, especially with the keyboard shortcuts.
I've had some issues with Dark GTK themes on Linux (Arc Dark) but I blame that on the theme not being written properly and not on this addon itself. The words for the folders would be almost the same color as the background of the bookmark list, but when I changed the theme the problem was fixed.
Glad you like the add-on.
You could use something like the Stylish add-on to tweak the font-color.
The URL to target would be "resource://jid0-qt2vxewb9xzbrlyapsjja4ebwou-at-jetpack/data/folderSelection.html".
And the CSS class to target would be ".linux .folder".