点击按钮刷新颜色
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>获取随机色</title>
<script type="text/javascript" src="https://code.jquery.com/jquery-3.1.1.min.js"></script>
<style type="text/css">
a{
float: left;
display: block;
margin: 50px;
width: 100px;
line-height: 100px;
text-align: center;
height: 100px;
color: #fff;
border-radius: 50px;
text-decoration: none;
}
.clear{clear: both;}
</style>
<script type="text/javascript">
$(document).ready(function(){
$('button').click(function(){
function aa(tag){
var len=document.getElementsByTagName(tag).length
for(var i=0; i<len; i++){
document.getElementsByTagName(tag)[i].style.backgroundColor='rgb('+Math.floor(Math.random()*256)+','+Math.floor(Math.random()*256)+','+Math.floor(Math.random()*256)+')'
}
}
aa('a')
})
})
</script>
</head>
<body>
<div>
<a href="#">1</a>
<a href="#">2</a>
<a href="#">3</a>
<a href="#">4</a>
<a href="#">5</a>
<button>点击换色</button>
<div class="clear"></div>
</div>
</body>
</html>待完善：点击按钮随机数待完善。