bandColor property
Band color of the bollinger band.
Default is Color(0x409e9e9e).
Widget build(BuildContext context) {
 return SfCartesianChart(
   indicators: <TechnicalIndicator<Sample, num>>[
     BollingerBandIndicator<Sample, num>(
       period: 2,
       standardDeviation: 3,
       bandColor: Colors.blue
     ),
   ],
 );
}
Implementation
final Color bandColor;