It would be a lot easier to make these changes if they were configurable in Preferences. Graphical UI elements like fonts and background colors are almost always things users can change. Seems like a lot of people's complaints never would have made it to this forum if they could have changed the applications behavior on their own. I know that was the first thing I did -- check the preferences for how to change the visuals back to what they were before.
Changing the look and feel was definitely a step backwards compared to the previous version. Wish I hadn't upgraded on the Apple App Store. You went from a rich look and feel to a stark one. Also add me to the list of folks who find it much harder on the eyes now. Net promoter score just went to a 6 from a 9.