// Bad:
element.setAttribute("style", "background-color: red;");
// Good:
element.style.backgroundColor = "red";
<html>
<body>
<p id="p2">Hello World!</p>
<script>
document.getElementById("p2").style.color = "blue";
</script>
<p>The paragraph above was changed by a script.</p>
</body>
</html>var elem = document.querySelector('#some-element');
// Set color to purple
elem.style.color = 'purple';
// Set the background color to a light gray
elem.style.backgroundColor = '#e5e5e5';
// Set the height to 150px
elem.style.height = '150px';