What’s the Firefox add-on to dim the whole page of a site?
Is there an extension or add-on like Stylish which lets you easily toggle back and forth between affected (Stylish) and standard (or untainted) view?
I've tried changing colors in Firefox (Settings > Content > Colors) but there is no quick toggle between the states.
Firefox or Google Chrome, whichever one has the extension. Doesn't matter since I'll switch to using that as my primary development browser.