On Ubuntu 14.04 (Unity) I wanted to change some KDE appearance settings, so I installed systemsettings. This turned out to be a bad idea, since it made the fonts in KDE applications ugly (see How to fix choppy fonts after using KDE System Settings?; unfortunately the solution there didn't work for me). I tried deleting KDE configuration files but this just made it worse, resetting the theme as well to the blue KDE default.
My question is, how do I reset KDE appearance settings to look like they're supposed to on Ubuntu? I guess Ubuntu ships its own configuration files, and if so, where do I get them?