Faça como eu fiz: o Widget contra ataca

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

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

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

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: Scaffold(
        appBar: AppBar(
          title: Text('Flutter: Primeiros Passos'),
        ),
        body: ListView(
          children: const [
            Quadro(Colors.pink, Colors.purple, Colors.blueAccent,Colors.white,Colors.lightBlueAccent,Colors.blueGrey,100,140),
            Quadro(Colors.pinkAccent, Colors.amber, Colors.lightBlue,Colors.black,Colors.amberAccent,Colors.purple,100,140),
            Quadro(Colors.purple, Colors.white, Colors.green,Colors.black,Colors.greenAccent,Colors.limeAccent,100,140),
            Quadro(Colors.pink, Colors.purple, Colors.blueAccent,Colors.white,Colors.lightBlueAccent,Colors.blueGrey,100,140),
            Quadro(Colors.pinkAccent, Colors.amber, Colors.lightBlue,Colors.black,Colors.amberAccent,Colors.purple,100,140),
            Quadro(Colors.purple, Colors.white, Colors.green,Colors.black,Colors.greenAccent,Colors.limeAccent,100,140),
            SizedBox(
              height: 100,
            ),
          ],
        ),
      ),
    );
  }
}

class Quadro extends StatelessWidget {
  final Color cor1;
  final Color cor2;
  final Color cor3;
  final Color cor4;
  final Color cor5;
  final Color cor6;
  final double largura;
  final double altura;

  const Quadro(this.cor1,this.cor2,this.cor3,this.cor4,this.cor5,this.cor6,this.largura,this.altura,{Key? key})
      : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Padding(
        padding: const EdgeInsets.only(top: 10),
        child: Container(
          height: altura,
          child: ListView(
            scrollDirection: Axis.horizontal,
            children: [
              Container(
                height: altura,
                width: largura,
                color: cor1,
              ),
              Container(
                height: altura,
                width: largura,
                color: cor2,
              ),
              Container(
                height: altura,
                width: largura,
                color: cor3,
              ),
              Container(
                height: altura,
                width: largura,
                color: cor4,
              ),
              Container(
                height: altura,
                width: largura,
                color: cor5,
              ),
              Container(
                height: altura,
                width: largura,
                color: cor6,
              )
            ],
          ),
        ),
      );
  }
}