Prefab Cannot Select Object Correctly

I have an enemy that follows the nearest of 4 players, Red, Blue, Yellow, and Green. I created a prefab of all four, and the enemy and in the script I adress the Transform of those players, called red, blue, yellow, and gree, but because you cannot select a transform of a prefab, I created 4 extra GameObject variables they are redObj, blueObj, yellowObj, and greenObj. I selected the prefabs in the Inspector and set them to the Obj variables, and then set the variables of their transforms (red, blue, ...) and set them to redObj.transform ect. The problem is when I create instances of the players and enemy, the enemy still has the prefabs selected for the Obj variables, and cannot get their transform, but I want it to select the instances for the Objs. Ill post the script and a screenshot of the problem. I hope I'm being clear enough! Thanks! #pragma strict

 public var myTransform : Transform; //current transform data of this enemy
 public var target : Transform; // The transform of the player
 
 public var redObj : GameObject;
 public var yellowObj : GameObject;
 public var greenObj : GameObject;
 public var blueObj : GameObject;
 
 private var red : Transform = redObj.transform;
 private var yellow : Transform = yellowObj.transform;
 private var green : Transform = greenObj.transform;
 private var blue : Transform = blueObj.transform;
 
 public var moveSpeed = 5.0;  // the rate at which the enemy follows the player
 public var rotationSpeed : float = 0.5; // the rate at which the enemy turns towards the player
 
 public var activateRange : float = 25.0;  // range at which enemy is activated
 public var chaseRange : float = 55.0; // range at which the enemy follows the player once activated
 public var dieRange : float = 1.0; // range at which the enemy blows up at the player.  This is not really relevent for the question, sorry
 
 
 
 public var activated : boolean = false; // if the enemy is activated or not
 var standing : boolean = true; // makes sure that the force is not added multiple times, because this function is called every Update() frame
 
 function Start(){
 
 }
  
 function Update(){
 
     closestPlayer();
     
     if (target == null){ // if there is no player
     return;
     }
     
     var range: float = Vector3.Distance(target.position, transform.position); // calculates the distance between the player and the enemy
     
     if(myTransform.rotation.eulerAngles.z == 90 || myTransform.rotation.eulerAngles.z == 270){
         standing = false;
         activated = true;
     }
     
     if(range <= activateRange){ // if the player is within activation range
         Activate(); // then activate.  see the Activate() function before continuing
     }
     
     
     if(activated){ // makes sure the enemy is activated
     
         if (range <= dieRange){ // tests to see if the ennemy is within the range to attack the enemy
             //Boom - still yet to do
         }
     
         else if (range <= chaseRange){ // if player is within the chase range, then chase
             // Roatates towards the player
             var relativePos : Vector3= myTransform.position - target.position; // finds the position of the player relative to the enemy
             var rotateTo2 : Quaternion = Quaternion.LookRotation(relativePos, Vector3.up); // turns it into a Quaternion, which is basically a rotation 
             rotateTo2.eulerAngles = Vector3(0, rotateTo2.eulerAngles.y, 90); // sets it to only look at the y value (so it rolls on its side)
             
             myTransform.rotation = Quaternion.Slerp(myTransform.rotation, rotateTo2, rotationSpeed * Time.deltaTime); // turns to it
             
             // Moves towards the player
             myTransform.Translate(-Vector3.forward * moveSpeed * Time.deltaTime);            
         }
     }
 }
 
 function Activate(){
     var random = Random.Range(1,9); // picks a random number between 1 and 8
     var xpos : float; // random x value for AddForce
     var zpos : float; // random z value for AddForce
     
     if(random == 1){ // if random == 1, choose random AddForce1
         xpos = 0.4;
         zpos = 0.4;
     } else if(random == 2){ // ect.
         xpos = -0.4;
         zpos = -0.4;
     }else if(random == 3){
         xpos = -0.4;
         zpos = 0.4;
     }else if(random == 4){
         xpos = 0.4;
         zpos = -0.4;
     }else if(random == 5){
         xpos = 0.6;
         zpos = 0;
     }else if(random == 6){
         xpos = -0.6;
         zpos = 0;
     }else if(random == 7){
         xpos = 0;
         zpos = 0.6;
     }else if(random == 8){
         xpos = 0;
         zpos = -0.6;
     }
     if(standing){ // again makes sure it is onle added once
         standing = false;
         rigidbody.AddForce(xpos, 1, zpos * 500); // knocks over enemy onto side 
         yield WaitForSeconds (2); // waits until enemy is on ground before running the follow part of the script
         activated = true; // activates the enemy
     
     }
 }
 
 function closestPlayer(){
     var rangeRed: float = Vector3.Distance(red.position, transform.position);
     var rangeYellow: float = Vector3.Distance(yellow.position, transform.position);
     var rangeGreen: float = Vector3.Distance(green.position, transform.position);
     var rangeBlue: float = Vector3.Distance(blue.position, transform.position);
     
     if(rangeRed < rangeYellow && rangeRed < rangeGreen && rangeRed < rangeBlue){
         target = red;
         return;
     } else if(rangeYellow < rangeRed && rangeYellow < rangeGreen && rangeYellow < rangeBlue){
         target = yellow;
         return;
     } else if(rangeGreen < rangeRed && rangeGreen < rangeYellow && rangeGreen < rangeBlue){
         target = green;
         return;
     } else if(rangeBlue < rangeRed && rangeBlue < rangeYellow && rangeBlue < rangeGreen){
         target = blue;
         return;
     }
 }