how can i display a flat background 2d image code example

Example: unity background camera

using UnityEngine;
using System.Collections;

public class Myclass: MonoBehaviour
{
    public Color Red = Color.red;
    
    public Camera cam;

    void Start()
    {
      
      
    }

    void Update()
    {
      
        cam.backgroundColor = Red;
    }
}