Ahhhh…removing the mchat_prosilver.css file forces a default to the ProDark style! At least now too I know which CSS file I need to edit if I ever want to change this!
OK! Found the Moderator Control Panel specific PHP files for the ProDark style for the Announcement Center. Those are now installed. Also, finally figured out how to get the forum logo on a black background and keep the background on the Announcement Center. This is pretty much now how I freaking want it!