import 'package:flutter/material.dart'; final Color darkBlue = Color.fromARGB(255, 18, 32, 47); void main() { runApp(MyApp()); } class MyApp extends StatelessWidget { @override Widget build(BuildContext context) { return MaterialApp( theme: ThemeData.dark().copyWith(scaffoldBackgroundColor: darkBlue), debugShowCheckedModeBanner: false, home: Scaffold( body: Center( child: MyWidget(), ), ), ); } } class MyWidget extends StatelessWidget { @override Widget build(BuildContext context) { return Container( decoration: BoxDecoration( shape: BoxShape.circle, border: Border.all(color: Colors.white, width: 2.0)), child: IconButton(onPressed: () {}, icon: Icon(Icons.add), padding: EdgeInsets.all(0))); } }