:header

index.html

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>New Page</title>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.0/jquery.min.js"></script>
</head>
<body>
<div id="main">
<p>Hello World!</p>
<h1>Header 1</h1>
<p>Hello World!</p>
<h2>Header 2</h2>
<p>Hello World!</p>
<h3>Header 3</h3>
<p>Hello World!</p>
<h4>Header 4</h4>
<p>Hello World!</p>
<h5>Header 5</h5>
<p>Hello World!</p>
<h6>Header 6</h6>
</div>
<script>
$(document).ready(function() {
$('#main>:header').css({'color': '#F00'});
});
</script>
</body>
</html>

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>New Page</title>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.0/jquery.min.js"></script>
</head>
<body>
<div id="main">
<p>Hello World!</p>
<h1>Header 1</h1>
<p>Hello World!</p>
<h2>Header 2</h2>
<p>Hello World!</p>
<h3>Header 3</h3>
<p>Hello World!</p>
<h4>Header 4</h4>
<p>Hello World!</p>
<h5>Header 5</h5>
<p>Hello World!</p>
<h6>Header 6</h6>
</div>
<script>
$(document).ready(function() {
$('#main>:header').css({'color': '#F00'});
});
</script>
</body>
</html>