backgroundColor property

The color which fills the SfCalendar header view background.

Defaults to null.

Using a SfCalendarTheme gives more fine-grained control over the appearance of various components of the calendar.

See also:

• SfCalendar.headerHeight, which allows to customize seize of the header view in calendar.
• Knowledge base: How to style a header

Widget build(BuildContext context) {
 return Container(
 child: SfCalendar(
     view: CalendarView.week,
     headerStyle: CalendarHeaderStyle(
         textStyle: TextStyle(color: Colors.red, fontSize: 20),
         textAlign: TextAlign.center,
         backgroundColor: Colors.blue),
   ),
 );
}