staticで変数をグローバル化しているけど，これは使用したのか不明．

lapTimeのboolをOn/Offしてて，ポーズ中は時間経過をスルー if(false)　させている．

ポーズ中は色を点滅＝　コルーチンのcolorSwitch()のとこ

これ，colorSwitch()のコルーチンを止めていないっぽいんで，7問だからいいけど，ポーズ以外はコルーチン止めたほうがいいかも．

using UnityEngine;
using System.Collections;
using System;
using UnityEngine.UI;


public class qwach : MonoBehaviour {

	public static float Quiztime = 0;//read from global
	public GameObject startPanel;
	public GameObject startKaitou;

	public Text timeTex; //Text用変数
	private bool lapTime;


	// Use this for initialization
	void Start () {
		Quiztime = 0f;
		startPanel.SetActive (true);
		lapTime = false;
		timeTex.color = Color.grey;
	}

	void Awake(){

		//StartCoroutine ("colorSwitch");
	}

	// Update is called once per frame
	void Update () {

		if (lapTime) {
			Quiztime += Time.deltaTime;
			timeTex.text = Quiztime.ToString ("f2") + "秒経過";
			;
			//timeTex.text = timeTex + "秒経過";
			//Debug.Log (time.ToString ());
		} else {
			//pause syori
			//StartCoroutine("colorSwitch");
				
			}
	
	}

	private IEnumerator colorSwitch(){
		while (true) {
	
				timeTex.color = Color.grey;
				yield return new WaitForSeconds (0.5f);
				timeTex.color = Color.white;
				yield return new WaitForSeconds (0.5f);
		}
	}


	public void qwPause(){
		StartCoroutine ("colorSwitch");
		lapTime = false;
	}

	public void qwStart(){
		StopCoroutine ("colorSwitch");
		timeTex.color = Color.white;
		lapTime = true;
	}


	public void qStart(){
		lapTime = true;
		startPanel.SetActive (false);
		timeTex.color = Color.white;

		startKaitou.SetActive (true);
	}

}