grayzone.dart

import 'package:flutter/material.dart';

void main() => runApp(const MyApp());

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  static const String _title = 'Flutter Code Sample';

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      title: _title,
      home: MyStatelessWidget(),
    );
  }
}

class MyStatelessWidget extends StatelessWidget {
  const MyStatelessWidget({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Container(
      decoration: const BoxDecoration(
        gradient: LinearGradient(
          begin: Alignment.centerLeft,
          end: Alignment.centerRight,
          colors: <Color>[
            Color(0xffffff00),
            Color(0xff0000ff)
          ], // yellow to blue
        ),
      ),
    );
  }
}