This was a five star extension prior to FF57, and now it just doesn't work. (1) No colours in inactive tabs (2) Text in inactive tabs unreadable, (3) Cannot drag with titlebar/tabbar.

Edit: I'm not trying to blame anyone, extension authors have done a fantastic job and I have used it for many years. It's just unfortunate that in it current state the extension is unusable. Colouring just the current tab is is nice, kinda less useful but at least it's something that can be used. The other two problems are unfortunately showstoppers.