<!DOCTYPE html>
<html>
<head>
<style>
span { color: red }
:checked + span { color: green }
input { display: none }
</style>

<body onload='document.getElementById("foo").setAttribute("checked", "checked");
              document.getElementById("bar").setAttribute("checked", "checked");'>
<input type="checkbox" id="foo"><span>There should be no red</span>
<input type="radio" id="bar"><span>There should be no red</span>
</body>
</html>