onclick will change the style javascript code example
Example 1: how to change style of an element using javascript
<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>
Example 2: how to change color on js
document.getElementBiId("your id").style.color = "your color";
//it can also be used as:
document.body.style.backgroundColor = "your color";