How to spawn prefabs by xMin and xMax position which will change the xmin and xmax position by it self when the screen size is changed?

I find the solution by finding the left and right edges of camera and it works good

here is the updated code

 using UnityEngine;
  using UnityEngine.UI;
  using System.Collections;
  
  public class SpawningColors : MonoBehaviour 
  {
      public GameObject[] ColorSprites;
      
  
      public float delayTimer = 0.5f;
      public float xMaxPosition, xMinPosition;
  
      private float timer;
  
      private int colorObjectNumbers;
  
  
      // Use this for initialization
      void Start () 
      {
          float camDistance = Vector3.Distance(transform.position, Camera.main.transform.position);
       
         rightBorder = Camera.main.ViewportToWorldPoint(new Vector3(0, 0, camDistance)).x;
         leftBorder = clampCamera.ViewportToWorldPoint(new Vector3(1, 0, camDistance)).x;
 
         timer = Time.deltaTime;
      }
      
      // Update is called once per frame
      void FixedUpdate ()
      {
          Spawning ();
  
      }
      public void Spawning ()
      {
          timer = timer - Time.deltaTime;
          if (timer <=0)
          {
              Vector3 scale = ColorSprites[colorObjectNumbers].transform.localScale;
              float rndmScale = Random.Range (0.8f, 1f);
              scale = new Vector3 (rndmScale, rndmScale, rndmScale);
              ColorSprites[colorObjectNumbers].transform.localScale = scale; // assign the new scale.
  
  
  
              Vector3 colorObjectPos = new Vector3 (Random.Range(leftBorder, 
              rightBorder),transform.position.y, transform.position.z );
         
              colorObjectNumbers = Random.Range(0, 24);
              Instantiate(ColorSprites[colorObjectNumbers], colorObjectPos, transform.rotation);
  
              timer = delayTimer;
          }
      }
  }