When I have understood everything correctly, you cannot edit the given ColorScheme or edit your own ColorScheme.

That is not entirely understandable.
I have an extensive WinForms desktop application in which the user can manage his own appointment types in the calendar.
He can freely assign the colors to the different appointment types. The infragistics ultimate scheduler is used.
I can assign a color to the appointments.
Now I'm writing a mobile app for it. The calenders should also be synchronized here.
Now I am faced with the dilemma, that the appointments in the calendars in the Windows application are different colors than in the mobile app.
It's hard to digest.

Is it so difficult to make 2 colors accessible in the ColorScheme?
Example:
resources.Add (new ScheduleResource ("ID1", "Bob Smith") {ColorScheme = ScheduleResourceColorScheme.Chocolate});

public enum ScheduleResourceColorScheme: System.Enum
 Chocolate Background: Argb (225, 121, 85, 72) Foreground: Argb (255, 68, 68, 68)

That can not be.

Is there any other way?

regards

Helmut