It works for about a day and then everything the theme changes turns white. I have to uninstall and reinstall every time it happens. But it's a small price to pay to be able to have a transparent theme.

With Firefox, I get Win10 Title bar color, just as hoped. So far, perfect. But with Thunderbird, just a pastel blue, so doesn't work there, for me. I'm running Win10, v1703, 64bit.

Looks very nice. Turning to solid white seems more like a Firefox issue to me. I tried myself to create such a transparent theme with no luck at all. A simple PNG with transparency apears opaque here.

Looks very great. But sometimes the transparent effekt was disabled after restart firefox.

Update: Unfortunately after a few days of use, it broke... browser and tabs turns solid white.

I have over 300 Windows 7 landscape wallpaper backgrounds that randomly changes every minute... the translucent look that peaks into my ever-changing wallpapers, similar to IE11, is just sublime... sticking to this one... great job Jirka!

An incredible theme through and through, and one of the few transparent ones where you can actually read the text without problem, regardless of the background.
Only problem is that it stops working every once in a while and you have to add it directly from here, as it won't wotk from the add-ons manager.
But that's more of a hassle than an actual problem, although it keeps this theme from being great until that's fixed.