<!DOCTYPE html>
<html>
<head>
<style>
span {
    color: blue;
}
</style>
</head>
<body>
  <div>
    <span>Should be colored blue.</span>
  </div>
  <div>
    <div>Should have no cool color.</div>
    <div>Should have no cool color either.</div>
  </div>
</body>