I am a long time mac user (since 10.0), and I have never actually looked at the appearance settings, so I checked just for you. In OS X 10.9 and 10.10 the only

I am a long time mac user (since 10.0), and I have never actually looked at the appearance settings, so I checked just for you. In OS X 10.9 and 10.10 the only real appearance settings are two color options, and the size of the side bars (scroll bars). You can also change the location, size and hiding settings for the dock. If you really like XML files then you probably have the option of changing the font, but it isn't straight forward. Personally I have only ever changed the dock location (usually to the right side) and the desktop image.