Calendar app doesn't set event color

Problems with setting event colors using your calendar app?

DAVx⁵ will enable event colors for synchronized calendars only when "Event colors" are enabled in the account settings. By default, event colors are disabled because many calendar apps have big problems with it.

So, if you want to synchronize event colors, make sure that the "Event colors" setting is enabled before trying to set the color in your calendar app.

If you have enabled event colors and your calendar app

crashes when you try to set the color for an event,
doesn't save the event when you set/change the color for this event,

it's usually a problem of the calendar app (and not DAVx⁵).

Setting event colors has successfully been tested with: (alphabetical order)

In contrast, the following calendar apps may crash or not save events when a color is assigned:

stock calendar / AOSP calendar
~~Google Calendar (bug report / discussion)~~ now Google Calendar doesn't allow to set colors for non-Google accounts at all
Samsung Calendar (formerly S Planner)

How can I fix it?

If you're experiencing this problem, you may either

use a calendar app that supports setting event colors (see above), or
disable event colors for the affected DAVx⁵ account and force synchronization.