Help with colors in Calendar on Mac

Hello SusanJT,

Thank you for reaching out to Apple Support Communities, and we'll be happy to help in any way we can. We understand you'd like to customize your calendar events. Try the steps listed ehre to see if htery resolve the issue: Change a calendar’s name or color on Mac - Apple Support

"Change a calendar’s name or color on Mac

A calendar is identified by its name and color, which you can change at any time.

Changing a calendar’s color changes the color of all of its events. If you want an event to have a different color, either change the color of the whole calendar or move the event to a calendar with a different color.

Rename a calendar

1. In the Calendar app  on your Mac, double-click the calendar’s name in the list, or force click the name.
2. If you don’t see the calendar list on the left, choose View > Show Calendar List.
3. Type a new name for the calendar.
4. You can’t rename the Exchange calendar named Calendar.

Change a calendar’s color

1. In the Calendar app  on your Mac, Control-click the calendar’s name in the calendar list.
2. If you don’t see the calendar list on the left, choose View > Show Calendar List.
3. Click to select a preset color, or click Custom Color to select a color from the Colors window.

Note: You can’t change the color of some calendars, such as the Birthdays calendar and the Siri Suggestions calendar."

We hope this helps.

Cheers!