You can change the colour on each of your calendars to help identify and organise activities. When you create or add a new shared calendar you can set the colour to one of eight available. You can use a colour more than once. You can change the colour of a calendar editing the Calendar properties, and assign appointments to a calendar when you create the appointment, or by single clicking an existing appointment.
The example to the right shows appointments from a personal calendar (green), a business calendar (orange) and a shared business calendar (blue). You can stack multiple calendar appointments on top of each other, as well as stacking appointments on top of appointments in the same calendar.