GUI闪烁效果[C#]

using UnityEngine;
using System.Collections;

public class MainBoardTop : MonoBehaviour
{
        public Texture2D Logo;
        public Texture2D SysInfo;
        public Texture2D FriInfo;
        public Texture2D IcoHelp;
        public GUIStyle style;
        public GUIStyle pathStyle;
        private bool displaySysLabel = false;
        private bool displayFriLabel = false;
        IEnumerator Start()
        {
                yield return StartCoroutine(flashSysLabel());
                yield return StartCoroutine(flashFriLabel());
        }
        IEnumerator flashSysLabel()
        {
                while(true)
                {
                        displaySysLabel = true;
                        yield return new WaitForSeconds(0.5f);
                        displaySysLabel = false;
                        yield return new WaitForSeconds(0.5f);
                }
        }
        IEnumerator flashFriLabel()
        {
                while(true)
                {
                        displayFriLabel = true;
                        yield return new WaitForSeconds(0.5f);
                        displayFriLabel = false;
                        yield return new WaitForSeconds(0.5f);
                }
        }
        void OnGUI()
        {
                GUI.BeginGroup(new Rect(0, 0, 300, 100));
                GUI.Button(new Rect(3,5,37,37),Logo,style);
                GUI.Button(new Rect(45,8,150,15),"test",pathStyle);
                if(displaySysLabel == true)
                {
                        GUI.Label(new Rect(45,25,16,16),SysInfo,style);
                }
                GUI.Label(new Rect(61,25,16,16),"0",style);
                if(displayFriLabel == true)
                {
                        GUI.Label(new Rect(77,25,16,16),FriInfo,style);
                }
                GUI.Label(new Rect(93,25,16,16),"0",style);
                GUI.Label(new Rect(108,25,16,16),IcoHelp,style);
                GUI.EndGroup();
        }
}