I was very hesitating between all those dark themes extensions listed on the mozilla website.
I scrolled down, check out the review, especially the negative one, the most popular extensions as well, then I gave a try to the Midnight Lizard...

The first thing i thought, it might have too many options, but with a nice list of themes, in just one or 2 click you do not have to do fine tuning as the list is well made.

On the other hand if you want to fine tune, you got ALL the tools you need.

What a great job on this add-on, i don't understand why it is not more popular.

Thanks a lot Pavel Agarkov for this gem