<script type="text/javascript">
       var p1 = document.getElementById('test1')
        p1.addEventListener('click',function(){
            //直接通过dom的方法改变颜色
            this.style.color = "red";
        },false);
  
    </script>

    <script type="text/javascript">
       $('#test2').click(function(){
     //通过包装成jQuery对象改变颜色
    $('this').css('color','blue');
     })
    </script>