If you use an alternative calendar on your Huawei P20 Pro, such as Google Calendar, you can assign calendar colors to different events in it.
But now it is the case that the calendar colors change regularly after you have set them, independently and automatically.
This means that the calendar color has to be changed each time. The reason for this is the synchronization with the Huawei calendar, even if it is not actively used.
The cause can only be solved by Huawei by optimizing the calendar app accordingly. However, the symptoms can be solved very well, so that the calendar colors on the Huawei P20 Pro are not constantly changed.
This works as follows:
Solution for calendar colors change automatically
For this all rights must be withdrawn from the Huawei calendar. This works as follows via the Android system settings:
1. Opens the settings of Android
2. Selects "Apps and Notifications" from
3. Next it goes to "Apps" - Searches in the list for "Calendar" and taps the calendar symbol of the Huawei calendar to
4. In the app info selects "Permissions". Now remove the permissions from all apps:
Slide the slider from "On" to "Off" Afterwards restarts the Huawei P20 Pro.
The calendar colors of the Google Calendar App should no longer change automatically. You have solved the problem without waiting for an App Update from Huawei.
By the way, the above trick also works for other calendar apps.