无法使用ThemeData为AppBar中的文本和Scaffold中的文本设置不同的颜色

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primaryTextTheme: TextTheme(
          headline6: TextStyle(color: Colors.red), // AppBar 文本颜色
        ),
        textTheme: TextTheme(
          bodyText1: TextStyle(color: Colors.blue), // Scaffold 文本颜色
        ),
      ),
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('AppBar Title'),
      ),
      body: Center(
        child: Text('Scaffold Body Text'),
      ),
    );
  }
}