The default “Moo blue” for unsynced calendar events is very close to the blue Legend uses for my synced Google Calendar that is “blue” in color. This makes it hard to spot events that are accidentally unsynced.
So I’m looking for a way to change it. The .date background-color attribute controls !date tags, but not the event blocks in a Calendar Pane. If these two functions were connected, that’d make sense to me, although separate controls would be nicer.