Flutter: Is there any way to change the row line color of DataTable?

Use Theme widget and overriding the dividerColor as shown below.

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'))
                  ],
                ),
              ]
          ),
        ),
      ),
    );
  }
}