Problems with color in prefab

Hello I have a prefab with this code:

 using UnityEngine;
 using System.Collections;
 
 public class ScorePopup : MonoBehaviour 
 {
 
     public float Speed = 1;
     private Color defaultColor;
 
     void Start () 
     {
         defaultColor = guiText.color;
     }
     
     void FixedUpdate () 
     {
         //Fade color alpha;
         Color col = guiText.color;
         col.a -= 1*Time.deltaTime;
         guiText.color = col;
 
         //Move object up while alpha isn't 0 and if so, reset its color and disable so it can be used again;
         if(col.a > 0)
         {
             transform.Translate(Vector3.up * Speed/1000);
         }
         else
         {
             gameObject.SetActive(false);
             guiText.color = defaultColor;
         }
     }
 }

 

I set the guitext color to red but for some reason it remains bright green! Can you help me?