I just learned that college and colleague are related, which I guess shouldn't be a surprise. One of my coworkers was confused by a reference to "cordial and collegial relations", thinking that "collegial" meant only "related to colleges" and not "related to colleagues".
College was borrowed from the French collége, which descends from the Latin collegium. It originally meant a body of colleagues, like a guild or other professional association. It eventually came to mean a group of scholars within or outside of a university, and because some universities only had one college, it became more or less interchangeable with university.
Colleague was borrowed from the French collègue, which comes from the Latin collēga, meaning literally 'chosen together'—that is, a partner or fellow in an association of some kind.