Вы можете использовать Тема виджет и переопределить dividerColor
Screen.jpg
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
home: MyHomePage(),
);
}
}
class MyHomePage extends StatefulWidget {
@override
State<StatefulWidget> createState() {
return _MyHomePageState();
}
}
class _MyHomePageState extends State<MyHomePage> {
@override
Widget build(BuildContext context) {
return Scaffold(
body: Center(
child: Theme(
data: Theme.of(context).copyWith(
dividerColor: Colors.green
),
child: DataTable(
columns: [
DataColumn(label: Text('Language')),
DataColumn(label: Text('Year'))
],
rows: [
DataRow(
cells: [
DataCell(Text('Go')),
DataCell(Text('2009'))
],
),
DataRow(
cells: [
DataCell(Text('Dart')),
DataCell(Text('2018'))
],
),
DataRow(
cells: [
DataCell(Text('Java')),
DataCell(Text('1992'))
],
),
]
),
),
),
);
}
}