I was able to fiddle with the CSS of the calendar to change it's colors--but I'm afraid I haven't a clue how to change the colors of the little mini calendar module displayed on the front site.
I remember setting it up so that the subscribe to this thread thing was not automatically checked every time a person posts. I don't like having that there, and being used to it not being there I didn't realize it was checked. Now I can't unsubscribe from this thread, and that's annoying.