如何更改flutter showAboutDialog中的文本按钮颜色？

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(title: Text('Flutter About Dialog Example')),
        body: Center(
          child: ElevatedButton(
            onPressed: () {
              showDialog(
                context: context,
                builder: (BuildContext context) {
                  return AlertDialog(
                    title: Text('关于'),
                    content: Text('这是一个关于对话框的示例。'),
                    actions: <Widget>[
                      TextButton(
                        child: Text('确定'),
                        style: TextButton.styleFrom(
                          primary: Colors.red, // 设置按钮文本颜色
                        ),
                        onPressed: () {
                          Navigator.of(context).pop();
                        },
                      ),
                    ],
                  );
                },
              );
            },
            child: Text('显示关于对话框'),
          ),
        ),
      ),
    );
  }
}