Can someone help me with GUI script what I have?

Hi Im using FPS kit by Aiden Studio and I want to add simple thing. If I click on button, player name in GUI will be red. There is script what generate GUI with everything. Please help me! using UnityEngine; using System.Collections;

 public class characterControls : MonoBehaviour {
 
 
     public int health = 100;
     public float speed = 10.0f;
     public float gravity = 10.0f;
     public float maxVelocityChange = 10.0f;
     public bool canJump = true;
     public float jumpHeight = 2.0f;
     private bool grounded = false;
 
     public SkinnedMeshRenderer[] skinnedPlayerMeshes;
     public MeshRenderer[] playerMeshes;
 
     public GameObject fpCam;
 
     public float bloodyScreenDuration = 3;
 
     public Texture[] bloodyScreens;
 
     float bloodTimer = 0;
 
     public PhotonView pv;
 
     public GameObject ragdoll;
 
 
     public GUISkin guiSkin;
 
     mouseLook mL;
 
     public bool isPaused = false;
 
     void Awake()
     {
         GetComponent<Rigidbody>().freezeRotation = true;
         GetComponent<Rigidbody>().useGravity = false;
         if (pv.isMine)
         {
             pv.RPC("setName", PhotonTargets.AllBuffered, PhotonNetwork.playerName);
      
             pv.RPC("updateWep", PhotonTargets.AllBuffered, PhotonNetwork.player.GetScore());
             mL = fpCam.GetComponent<mouseLook>();
         
         }
 
       
     }
 
     [PunRPC]
     public void setName(string nm)
     {
         gameObject.name = nm;
     }
 
     void Update()
     {
         if (bloodTimer > 0)
         {
             bloodTimer -= Time.deltaTime;
         }
     }
 
     void FixedUpdate()
     {
         if (grounded && pv.isMine)
         {
             // Calculate how fast we should be moving
             Vector3 targetVelocity = new Vector3(Input.GetAxis("Horizontal"), 0, Input.GetAxis("Vertical"));
             targetVelocity = transform.TransformDirection(targetVelocity);
             targetVelocity *= speed;
 
             // Apply a force that attempts to reach our target velocity
             Vector3 velocity = GetComponent<Rigidbody>().velocity;
             Vector3 velocityChange = (targetVelocity - velocity);
             velocityChange.x = Mathf.Clamp(velocityChange.x, -maxVelocityChange, maxVelocityChange);
             velocityChange.z = Mathf.Clamp(velocityChange.z, -maxVelocityChange, maxVelocityChange);
             velocityChange.y = 0;
             GetComponent<Rigidbody>().AddForce(velocityChange, ForceMode.VelocityChange);
 
             if (health <= 0)
             {
                 pv.RPC("Die", PhotonTargets.AllBuffered, null);
             }
 
             // Jump
             if (canJump && Input.GetButton("Jump"))
             {
                 GetComponent<Rigidbody>().velocity = new Vector3(velocity.x, CalculateJumpVerticalSpeed(), velocity.z);
             }
 
             isPaused = Input.GetKey(KeyCode.Tab);
 
             mL.enabled = !isPaused;
 
             if (isPaused)
             {
                 Cursor.lockState = CursorLockMode.None;
                 Cursor.visible = true;
             } else
             {
                 Cursor.lockState = CursorLockMode.Locked;
                 Cursor.visible = false;
             }
             if (Input.GetKeyUp(KeyCode.F5))
             {
                 pv.RPC("gotKill", PhotonTargets.AllBuffered, "loser");
             }
         }
 
         // We apply gravity manually for more tuning control
         GetComponent<Rigidbody>().AddForce(new Vector3(0, -gravity * GetComponent<Rigidbody>().mass, 0));
 
         grounded = false;
     }
 
     void OnCollisionStay()
     {
         grounded = true;
     }
 
     float CalculateJumpVerticalSpeed()
     {
         // From the jump height and gravity we deduce the upwards speed 
         // for the character to reach at the apex.
         return Mathf.Sqrt(2 * jumpHeight * gravity);
     }
 
     string killerWep = "World";
     string killer = "Null";
 
     [PunRPC]
     public void ApplyDamage(int dmg, string wepName, string kilr)
     {
         if (kilr != gameObject.name)
         {
             health -= dmg;
             killerWep = wepName;
             killer = kilr;
 
             if (pv.isMine)
             {
                 blood = bloodyScreens[Random.Range(0, bloodyScreens.Length)];
                 bloodTimer = bloodyScreenDuration;
 
                 if (health <= 0)
                 {
                     pv.RPC("Die", PhotonTargets.AllBuffered, null);
                 }
             }
         }
     }
 
     Texture blood;
 
     Vector2 scroll = Vector2.zero;
 
     void OnGUI()
     {
         GUI.skin = guiSkin;
         GUI.Box (new Rect (10, Screen.height - 100, 145, 30), "HP | " + health);
         if (bloodTimer > 0) {
             Color c = Color.white;
             c.a = bloodTimer;
             GUI.color = c;
             GUI.DrawTexture (new Rect (0, 0, Screen.width, Screen.height), blood, ScaleMode.StretchToFill);
 
         }
         if (isPaused) {
             GUILayout.BeginArea (new Rect (Screen.width / 2 - 500, Screen.height / 2 - 200, 300, 500));
             GUILayout.BeginVertical ("Box");
             GUILayout.Label ("Paused");
             scroll = GUILayout.BeginScrollView (scroll, "Window");
             GUILayout.BeginHorizontal ();
             GUILayout.Label ("Player ");
             GUILayout.Label ("Kills");
             GUILayout.Label (" Weapon");
             GUILayout.EndHorizontal ();
             foreach (PhotonPlayer pl in PhotonNetwork.playerList) {
                 GUILayout.BeginHorizontal ("Box");
                 GUILayout.Label (pl.NickName + " ");
                 GUILayout.Label (pl.GetScore () + " ");
                 GUILayout.EndHorizontal ();
             }
             GUILayout.EndScrollView ();
             if (GUILayout.Button ("Suicide")) {
                 if (pv.isMine) {
                     pv.RPC ("ApplyDamage", PhotonTargets.AllBuffered, 10000, "Suicide", "Self");
                 }
             }
             if (GUILayout.Button ("Resume")) {
                 isPaused = false;
             }
             if (GUILayout.Button ("Disconnect")) {
                 PhotonNetwork.LeaveRoom ();
                 UnityEngine.SceneManagement.SceneManager.LoadScene (1);
             }
 
             GUILayout.EndVertical ();
             GUILayout.EndArea ();
         }
     }
 
     bool dead = false;
 
     [PunRPC]
     public void Die()
     {
         if (!dead)
 
         {
             dead = true;
             Destroy(gameObject);
             if (pv.isMine)
             {
                 Cursor.lockState = CursorLockMode.None;
                 Cursor.visible = true;
                 PhotonNetwork.Instantiate(ragdoll.name, transform.position, transform.rotation, 0);
                 GameObject.Find("_Room").GetComponent<roomManager>().isSpawned = false;
                 GameObject.Find("_Room (2)").GetComponent<roomManager>().isSpawned = false;
 
                 GameObject.Find("_Network").GetComponent<PhotonView>().RPC("getKillFeed", PhotonTargets.All, PhotonNetwork.player.NickName, killer, killerWep);
                 if (GameObject.Find(killer) != null)
                 {
                     GameObject.Find(killer).GetComponent<PhotonView>().RPC("gotKill", PhotonTargets.AllBuffered, PhotonNetwork.playerName);
                 }
             }
         }
     }
 
     [PunRPC]
     public void gotKill(string victim)
     {
         if (pv.isMine)
         {
             PhotonNetwork.player.AddScore(1);
             pv.RPC("updateWep", PhotonTargets.AllBuffered, PhotonNetwork.player.GetScore());
         }
         Debug.Log("Killed " + victim + "! Score: " + PhotonNetwork.player.GetScore());
         
     }
 
     [PunRPC]
     public void destroy()
     {
         Destroy(gameObject);
     }
 }