Works nicely on the email accounts columns. If it would be possible to apply also to the sections listing the emails that would be very useful for some vision impaired users.
I have just convinced my 70 year old dad to use Thunderbird as a way to escape the multiple captcha needed to access the websites of his email accounts have been making his life pretty miserable. Allowing a direct access to his emails (no captcha anymore), Thunderbird is putting him back in contact with social interactions and providing him again the feeling of being connected to the rest of developed world. Quickly though, he has felt that the background (white) and stars (yellow) colors were not allowing him to see the latter. I wonder if it would be possible to apply Monterail on the section of the page listing the emails so that these stars would stand out from the background. This would make Thunderbird more "vision impaired friendly".
I feel really comfortable working with this theme. Items are clearly laid out, easy to find and read. So, far, the only improvement I would suggest is changing the black font used for the text in the top-most tabs to white when unselected.
Brilliant skin best I have used that fits by needs.
I only have one recommendation to the developer, the three icons in the top right hand corner are black, this clashes with the background colour of the skin and heuristically makes it hard to see when my laptop screen is slightly low, may I humbly ask him to change the colour to white. This will then match the rest of the colour icons in the top left hand corner and make this skin perfect.