Type `UnityEngine.Renderer' does not contain a definition for `color' and no extension method `color' of type `UnityEngine.Renderer' could be found (are you missing a using directive or an assembly reference?)

 public class ControlTitleScene : MonoBehaviour {
     
     public Transform targetPoint; //target camera move to point 
     public AudioSource bgm; //main background music
     public GameObject titleText,pressStart,buttonNew,buttonLoad,whiteScreen; //button,GUI
     public AudioClip buttonSound; //button sound effect
     
     //Private Variable
     private int titlePattern = 0;
     private float alpha = 0.5f;
     
     
     // Use this for initialization
     void Start () {
         
         //Set default variable
         alpha = 0.5f;
         whiteScreen.SetActive(true);
     
     }
     
     // Update is called once per frame
     void Update () {
         
         //Pan camera
         transform.position = Vector3.MoveTowards(transform.position, targetPoint.position, 3 * Time.deltaTime);    
         
         if(titlePattern == 0)
         {
             if(alpha > 0)
             {
                 alpha -= Time.deltaTime * 0.2f;
                 whiteScreen.GetComponent<Renderer>().color = new Color(.5f,.5f,.5f, alpha);
             }else
             {
                 bgm.Play();    
             }
             
             if(transform.position.z >= -27.0f)
             {
                 titlePattern = 1;
                 alpha = 0;
                 titleText.SetActive(true);
             }
             
         }
         
         if(titlePattern == 1)
         {
             if(alpha < 0.5f)
             {
                 alpha += Time.deltaTime * 0.5f;
                 titleText.GetComponent<Renderer>().color = new Color(.5f,.5f,.5f, alpha);
             }else
             {
                 titlePattern = 2;
                 pressStart.SetActive(true);    
             }
         }
         
         if(titlePattern == 2)
         {
             //Show press start
             
             if(Input.anyKey)
             {
                 pressStart.SetActive(false);
                 if(buttonSound != null)
                 {
                     AudioSource.PlayClipAtPoint(buttonSound,transform.position);    
                 }
                 titlePattern = 3;
             }
         }
         
         if(titlePattern == 3)
         {
             //Show button new game , load game
             buttonNew.SetActive(true);
             buttonLoad.SetActive(true);
         }
         
     }
 }