Generate Random Background Color In Flutter Android App

import 'package:flutter/material.dart';
import 'dart:math';

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

class MyApp extends StatelessWidget {

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
        home: Scaffold(
            body: View()
        )
    );
  }
}

class View extends StatefulWidget {
  ViewState createState() => ViewState();
}

class ViewState extends State{
  Color colorCode = Color(0xFF01579B);
  final Random random = Random();
  generateRandomColor(){
    Color tmpColor = Color.fromARGB(
      random.nextInt(256),
      random.nextInt(256),
      random.nextInt(256),
      random.nextInt(256),
    ) ;

    setState(() {
      colorCode = tmpColor ;
    });

  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
        backgroundColor: colorCode,
        appBar: AppBar(
          backgroundColor: Colors.pink,
            title: Text('Generate Random Background Color'
            )),
        body: Center(
            child: Container(
                margin: const EdgeInsets.fromLTRB(10, 0, 10, 0),
                child:
                RaisedButton(
                  onPressed: () => generateRandomColor(),
                  child: Text('Generate Random Background Color'),
                  textColor: Colors.white,
                  color: Colors.pink,
                  padding: EdgeInsets.fromLTRB(12, 12, 12, 12),
                ))
        )
    );
  }
}