<!DOCTYPE html>
<html>
<head>
<style>
.siblings * {
display: block;
border: 2px solid lightgrey;
color: lightgrey;
padding: 5px;
margin: 15px;
}
</style>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.2/jquery.min.js"></script>
<script>
$(document).ready(function(){
$("h2").next().css({"color": "red", "border": "2px solid red"});
});
</script>
</head>
<body class="siblings">
<div>div (parent)
<p>p</p>
<span>span</span>
<h2>h2</h2>
<h3>h3</h3>
<p>p</p>
</div>
</body>
</html>