如果要使用浏览器中运行的客户端代码(javascript)更改div的颜色，请执行以下操作:

If you want to alter the color of the div with client side code (javascript) running in the browser, you do something like the following:

<script>
 var fooElement = document.getElementById("foo");
 fooElement.style.color = "red"; //to change the font color
</script>