I see what you mean now...yes, that file path includes the theme folders. If you do want to use it for your clock alarms as well, just do the same thing with the RibbonAlarm attachment (unzip, drag folder to /Library/Themes, activate in WB). But then your OpenNotifier alerts and your clock alarms would be the same ribbon icon, unless you wanted to go in and change the ribbon color before SSHing the theme.
By the way, the OpenNotifier theme replaces the exclamation point only--for the ribbon to show up you need to choose the exclamation point in the ON settings. Have fun!