In order to filter your Calendar by courses or groups, click the color box next to the Calendar . The calendar can show up to 10 courses and/or groups at a time. In this example, not all of the calendars are being shown.
Note: Canvas will assign an arbitrary color for each calendar unless a custom color is chosen. Each calendar contains 15 default colors, but you can create any color of your choice by selecting the More icon  and inserting a Hex code .
For more information, please visit:
Canvas Student Guide