color property
Color of the minor grid lines.
Defaults to null.
Widget build(BuildContext context) {
    return Container(
        child: SfCartesianChart(
            primaryXAxis: NumericAxis(
            minorTicksPerInterval: 5,
            minorGridLines: MinorGridLines(
            color: Colors.red,
         ),
         )
        ));
}
Implementation
final Color? color;