Friul

Theme with the official Friulian Flag.

Space - wonderful world

space, wonderful world, stars, mathematic

The Hunting of the Snark 2

Chocolate brown colored theme with a detail from an Illustration by Henry Holiday to Lewis Carroll's "The Hunting of the Snark"

Mail Delivery 4K (2023)

Mail Delivery 4K (2023) theme for Thunderbird 100+ and 4K monitors.

Thunderbird Daily Suave

Based on the "Thunderbird Suave" theme by aramaicus.

Illidan World of Warcraft

World of Warcraft Illidan the Burning Crusade Wrath of the lick king

yahane_pattern

yahane_pattern, BY: HEKISU1

Mail Delivery 4K (2004)

Mail Delivery 4K (2004) theme for Thunderbird 100+ and 4K monitors.

dark myth

Asus ROG Leather Small Badge

Asus ROG inspired theme with smaller badge to better suit some resolutions

irasutoya01

Thunderbird 78 以降用に使えるテーマを練習用に作ってみました。
Very simple theme, which uses only public domain illustrations.

summersmile

Summersmile adds a lively flair to Thunderbird with a sunny yellow background, playful smiley graphics, and a "sunshine and smiles" theme that refreshes your email experience.