Hi Donjet,
Thank you for contacting Syncfusion support.
We have checked the reported query “change selected dates color in SfCalendar based on condition” from our end. We regret to inform you that as per implementation of SfCalendar, the SelectedDateColor property is used to change the color for all the Selected dates and there is no support available for the changing the selected dates based on the condition.
We hope this helps. Please let us know if you need any further assistance.
Regards,
SaiGanesh Sakthivel