Hello!
Great. Thanks in advance!
Also, if you'll have time remaining after: With FF56 (beta) some new sporadically appearing issue came up.
Sometimes the color edits are not applied: always when you create a new one or disable+enable an old one, and stay that way for open tabs, they'll only be applied when you load the pages in a new tab. When opening a link in gmail, which was fixed by reinstalling the addon (but this issue came back once so I reinstalled again). Sometimes when the tab was the active tab on startup wouldn't have the edits applied, I think this happened simultaneously to the gmail thing and got fixed by the same thing.