AppBar icon override

main.dart

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    final theme = ThemeData.light(useMaterial3: true);
    return MaterialApp(
      theme: ThemeData(
        useMaterial3: true,
        appBarTheme: theme.appBarTheme.copyWith(
          // EXPECTED: We expect to see these values for our icon color.
          actionsIconTheme: const IconThemeData(
            color: Colors.red,
          ),
          iconTheme: const IconThemeData(
            color: Colors.blue,
          ),
        ),
        // ACTUAL: Instead, we see this value (try commenting this parameter out):
        iconButtonTheme: IconButtonThemeData(
          style: IconButton.styleFrom(
            foregroundColor: Colors.yellow,
          ),
        ),
      ),
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        appBar: AppBar(
          leading: appBarButton(),
          actions: [appBarButton()],
          title: const Text('App Bar'),
        ),
        body: Center(
          child: MyWidget(),
        ),
      ),
    );
  }

  Widget appBarButton() => IconButton(
        tooltip: 'Settings',
        icon: const Icon(Icons.settings),
        onPressed: () {},
      );
}

class MyWidget extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.all(50.0),
      child: Text(
        'Icons above should be inheriting color values from AppBarTheme.iconTheme and AppBarTheme.actionsIconTheme. However, the icons are using any IconButtonTheme override present in the theme.',
        style: Theme.of(context).textTheme.bodySmall,
      ),
    );
  }
}