White Glossy Look
I like simple themes so I'd use this one.
Rated 5 out of 5 stars by Naumov on July 9, 2018
Categorized as a Thunderbird theme. Click the "Add to Thunderbird" button and it says "Only for Firefox". Mozilla is somewhat confused. I suppose the theme is okay.
Not a real rating, I've never seen it.
Rated 1 out of 5 stars by Fred on July 3, 2018
Rated 5 out of 5 stars by Paro on June 28, 2018