wwwebtarget,
<!DOCTYPE html>
<html>
<head>
<title>Untitled</title>
<meta charset="utf-8">
<style type="text/css">
.active {
background-color: #FF0000;
color: #FFFFFF;
}
</style>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>
<script>
$(function() {
$("div.status>span.online").filter(()=> Math.random() < .3).addClass("active");
});
</script>
</head>
<body>
<div class="status"><span class="online">01</span></div>
<div class="status"><span class="online">02</span></div>
<div class="status"><span class="online">03</span></div>
<div class="status"><span class="online">04</span></div>
<div class="status"><span class="online">05</span></div>
<div class="status"><span class="online">06</span></div>
<div class="status"><span class="online">07</span></div>
<div class="status"><span class="online">08</span></div>
<div class="status"><span class="online">09</span></div>
<div class="status"><span class="online">10</span></div>
</body>
</html>