Rated 5 out of 5 stars

A very clear, colorful and compact theme. Now working again with Thunderbird 52 and hopefully with further generations. This addon allows to hold the familiar program surface beyond all the years, I like it.

Rated 3 out of 5 stars

I'm sorry to see my favorite theme obviously no longer supported.
Since TB45 the close-button on tabs has gone. In the edit-window the symbols-bar is corrupted by the new fontsize-icon: Instead of this symbol all edit-icons are shown, arranged in two lines!
Well, no more work done on that for 2½ years now. R.I.P.
– Does anybody know an alternative???

This review is for a previous version of the add-on (1.3.0). 

Version 1.4.0 fixes all of these issues, and quite a few others. Hope you'll try it out!