Atom syntax color? How do I reset it?

Something set my Atom interface background to blue with keywords and procedure names also set to blue, comments to medium gray, and select highlight to medium brownish. In other words, the interface is now useless. I am trying to edit Python files. I uninstalled and re-installed Atom, but the problem persists. I have not encountered an equally difficult for the user to customize editor since the 70s, so I presume that I missing something. How do I reset Atom to useable high contrast colors?