main.dart

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(
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        body: Center(
          child: MyWidget(),
        ),
      ),
    );
  }
}

class MyWidget extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return SizedBox(
      height: 200,
      child: Row(
        children: [
          Expanded(
            child: Container(
              margin: EdgeInsets.all(18.0),
              color: Colors.red,
            ),
          ),
          Expanded(
            child: Container(
              margin: EdgeInsets.all(18.0),
              color: Colors.blue,
            ),
          ),
          Expanded(
            child: Container(
              margin: EdgeInsets.all(18.0),
              color: Colors.yellow,
            ),
          ),
        ],
      ),
    );
  }
}