Occasionally, the color of your calendar may revert to its default setting. This can be fixed by following these steps:
- Open Google Calendar in a browser.
- Tap "Desktop version" at the bottom of the screen under "View."
- Under [My Calendars] on the left, select the calendar whose color you want to change. A button with three dots will appear on the right. Tap it and select your preferred color.
- It may take some time for the color to update in the app (up to one day).
Thank you for your understanding.