[dart] How do I set the background color of my main screen in Flutter?

There are many ways of doing it, I am listing few here.

  1. Using backgroundColor

    Scaffold(
      backgroundColor: Colors.black,
      body: Center(...),
    )
    
  2. Using Container in SizedBox.expand

    Scaffold(
      body: SizedBox.expand(
        child: Container(
          color: Colors.black,
          child: Center(...)
        ),
      ),
    )
    
  3. Using Theme

    Theme(
      data: Theme.of(context).copyWith(scaffoldBackgroundColor: Colors.black),
      child: Scaffold(
        body: Center(...),
      ),
    )