Hi David,
Attached is a sample for formatting the header. I have created this sample with version 4.3.0.30
http://www.syncfusion.com/Support/user/uploads/FormattingDDCalSample.zipThe DropDownCalendar control has many style property such as CalendarStyle, DayHeaderStyle, DayStyle, etc., which is present in the Style Category of the properties window that can be used to set the Font and Color attributes of the Calendar control.
Please let us know if you have any further queries.
Regards,
Sharmila