Thank you for posting this. I was horrified to discover the interface changed to a disorganized, cluttered, monotone blob of unintelligible text with no borders or demarcations for fields, tabs, labels, etc. If the objective was to make the browser counterproductive and unusable, they succeeded.

Hi , There's a Firefox theme on the addons site called Photon Colors, which I found helps a lot.

Go to https://addons.mozilla.org/firefox/addon/photon-colors/ and click on Install Theme.