Rated 5 out of 5 stars

Clocking in at an unbelievably small 309 kb this theme and Frank's Metal Lion Silver make SeaMonkey look 10 years younger.
Easy on the eyes with meticulous attention to detail inside and out, add Patrick Dempsey's Sea Fox Extension and enjoy SM 2016.

@As for not being Firefox compatible Frank does have similar Fx themes..Nudge nudge win wink..

https://addons.mozilla.org/en-US/firefox/user/frank-lion/

This review is for a previous version of the add-on (2.0.3.3).