How to change Status Bar and App Bar color in Flutter?

UPDATE:

Scaffold(
  appBar: AppBar(
    systemOverlayStyle: SystemUiOverlayStyle(
      systemNavigationBarColor: Colors.blue, // Navigation bar
      statusBarColor: Colors.pink, // Status bar
    ),
  ),
)

---

Old solution (still works)

Both iOS and Android:

appBar: AppBar(
  backgroundColor: Colors.red, // status bar and navigation bar color
  brightness: Brightness.light, // status bar brightness
)

---

Only for Android (More flexibility)

You can use SystemChrome class to change Status bar and Navigation bar color. First import

import 'package:flutter/services.dart';

After this, you need to add following lines (better place to put these lines is in your main() method)

void main() {
  SystemChrome.setSystemUIOverlayStyle(SystemUiOverlayStyle(
    systemNavigationBarColor: Colors.blue,
    statusBarColor: Colors.pink,
  ));
}

---

I tried the method SystemChrome.setSystemUIOverlayStyle(), as far as I tested (Flutter SDK v1.9.1+hotfix.2, running on iOS 12.1) it works perfect for Android. But for iOS, e.g. if your first screen FirstScreen() doesn't have an AppBar, but the second SecondScreen() does, then at launch the method does set the color in FirstScreen(). However, after navigating back to FirstScreen() from SecondScreen(), the status bar color becomes transparent.

I come up with a hacky workaround by setting an AppBar() with zero height, then status bar's color gets changed by the AppBar, but the AppBar itself is not visible. Hope it would be useful to someone.

// FirstScreen that doesn't need an AppBar
@override
Widget build(BuildContext context) {
  return Scaffold(
    appBar: PreferredSize(
        preferredSize: Size.fromHeight(0),
        child: AppBar( // Here we create one to set status bar color
          backgroundColor: Colors.black, // Set any color of status bar you want; or it defaults to your theme's primary color
        )
      )
  );
}

// SecondScreen that does have an AppBar
@override
Widget build(BuildContext context) {
  return Scaffold(
    appBar: AppBar()
  }
}

Here is the screenshot of FirstScreen in iPhone Xs Max iOS 12.1: