Блондинка,
<!DOCTYPE html>
<html>
<head>
<title>Untitled</title>
<meta charset="utf-8">
<style>
.a1 { background: white; text-align: left; }
.a1 span{ color: blue; }
.a1.act { background: blue; text-align: left; }
.a1.act span{ color: white; }
</style>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>
<script>
$(function() {
$(".a1").on("click", function() {
$(this).toggleClass("act")
})
});
</script>
</head>
<body>
<div class="a1"><span>text one</span></div>
</body>
</html>