When working with multiple calendars, the color of the calendar becomes very important. Different colors will make it much easier to distinguish one calendar from another. Please see below how to change the calendar color:
Step 1: Click the "Calendar" button from the taskbar;
Step 2: Right click anywhere on your calendar, and choose "Color" from the dialog box;
Step 3: Choose a color from the list, and the calendar color will be changed right away.