A video showing the new categorization in Plasma 5's System Settings.
Also a sneak preview of some work in progress new interface, built in QtQuick around Plasma's new Breeze style. Very experimental, though.
We ship I think more than 12 different colour schemes in the default install you can choose from. The colours in the video are the default, and they're relatively conservative. Your mileage and taste may vary, so it's easy enough to change.