[Projeto] Faça como eu fiz: uma nova tela

import 'package:flutter/material.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Primeiro App',
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.redAccent.shade700),
        useMaterial3: true,
      ),
      home: Container(
          color: Colors.black,          
          child: Column(
            mainAxisAlignment: MainAxisAlignment.spaceEvenly,
            children: [
              Stack(
                children: [
                  Row(
                      mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                      children: [
                        Container(
                          color: Colors.redAccent.shade700,
                          height: 100,
                          width: 100,
                        ),
                        Container(
                          color: Colors.orangeAccent.shade700,
                          height: 100,
                          width: 100,
                        ),
                        Container(
                          color: Colors.yellowAccent.shade700,
                          height: 100,
                          width: 100,
                        ),
                      ]),
                ],
              ),
              Stack(
                children: [
                  Row(
                      mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                      children: [
                        Container(
                          color: Colors.greenAccent.shade700,
                          height: 100,
                          width: 100,
                        ),
                        Container(
                          color: Colors.blueAccent.shade100,
                          height: 100,
                          width: 100,
                        ),
                        Container(
                          color: Colors.blueAccent.shade700,
                          height: 100,
                          width: 100,
                        ),
                      ]),
                ],
              ),
              Stack(
                children: [
                  Row(
                      mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                      children: [
                        Container(
                          color: Colors.purpleAccent.shade700,
                          height: 100,
                          width: 100,
                        ),
                        Container(
                          color: Colors.pink.shade600,
                          height: 100,
                          width: 100,
                        ),
                        Container(
                          color: Colors.white,
                          height: 100,
                          width: 100,
                        ),
                      ]),
                ],
              ),
            ],
          )),    
      
    );
  }
}