span.foo {
background-color: navy;
color: #BFD;
}
span.bar {
background: rgba(105, 0, 12, .62);
color: hsl(30, 100%, 50%);
}
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8" />
<title>Example</title>
<style>
/* Also works here */
a.not-a-class {
color: red;
}
</style>
<body style="color: black">
</body>
</html>