Users with the Practice permission can select Persons & Institutions | Practice | Appointment Categories from the navigation menu to set colors for specific categories.
This allows you to customize the category. Some common categories that some practices may use is colors to indicate Cancellations, Telehealth, Specific CPT Codes, or any grouping that a practice wants to associate. Colors can be assigned to specific CPT codes so the color will be default to the assigned category. The category is also an option when creating an appointment and can be assigned to a specific appointment. Unfortunately, colors cannot be added or removed from the list.