<!DOCTYPE html>
<html>
<head>
<script>
function display()
{
var col=document.getElementById("demo");
col.style.color="#FF0000";
}
</script>
</head>
<body>
<h1>My First JavaScript</h1>
<p id="demo">click on the button below.....</p>
<button onclick="display()">Display</button>
</body>
</html>document.getElementBiId("your id").style.color = "your color";
//it can also be used as:
document.body.style.backgroundColor = "your color";var span = document.getElementsByTagName("span")[0];
span.style.color = "red";