by steva (Developer) on March 15, 2016 · permalink

Thanks for the feedback, but if you have an issue could you, please, use the support link (next to the add-on description) and follow the instructions described in the add-on description, thank you. By the way, what you exactly mean by partially black and partially white? Doesn't sound so clear.
By the way, if you install Thunderbird 45beta and TT DeepDark 11beta8, the top part looks black (but the fix is not available for Thunderbird version under the beta one, because it doesn't work with prior versions).

Now more precisely about the title bar, the theme doesn't customize the default Windows 10 color (no complete themes for Thunderbird and Firefox does), it simply puts a dark bar with caption buttons above the default Windows one (the default Thunderbird theme behaves also that way, it is a workaround to "hide" the white Win10 default titlebar to give the illusion that the Win10 bar has another color). This workaround only works for the main Thunderbird window. This means that when you open the email compositor or any other Thunderbird window, the default Win10 bar will be visible. It is a limitation which complete themes can do nothing for. Complete themes can't customize Windows frame colors. Actually they can only customize the Thunderbird UI. So what the default theme doesn't cover can't be covered by complete themes either.