One type of sub-calendar that you can use in the Calendars tool are Event or Lead sub-calendars.
Event sub-calendars are automatically created when you create a new Event, and the same goes for Lead sub-calendars. You cannot create an Event or Lead sub-calendar on its own without creating an Event or Lead, so to create one you must click on the "Events" tab in the main navigation bar and click on the "Add Event" button (and same for Leads). There you can select the color for the Event/Lead sub-calendar.
Also, when you assign Contacts to an Event or Lead, those people are also automatically assigned to that Event/Lead sub-calendar and will have access to it.
To edit the name of an Event or Lead sub-calendar, you must edit the name of the Event/Lead itself. You can only delete/remove an Event/Lead sub-calendar if you archive an Event or if you close or delete a Lead.
Video Tip - Go to the 0:39 mark of the video to view information on using Event and Lead sub-calendars.