>>1435519I was using this CSS script designed to fit Appows Dusk but I disabled it before I activated Mono's and got that blue bar back. Just randomly tried turning them both off, activating the Appows script then Mono's and it works great, aside from on websites with different colored backgrounds as the tabs are slightly larger than the bar and it's only noticeable on them.. (Though I haven't closed/reopened Nightly yet so I'm not entirely sure if it stays like this)
I believe this was the CSS script:
http://pastebin.com/NTj5PNEkpic related, this is what it looks like now