"Hi chaps, The catchily titled extension 'ToggleUseDocColors' is now released under GPLv3. It did have no license attached, but after an email to the author explaining why it would be a good thing to add it now does :-) He asked that in return I post a review to addons.mozilla.org (as apparently several reviews are needed before an addon can be marked as not 'experimental' there), which I was more than happy to do. The license is attached to the addon's entry on the website, at ..."