emptyindorill, уже лучше...
<!DOCTYPE html>
<html>
<head>
<meta http-equiv='Content-Type' content='text/html; charset=windows-1251' />
<script src='https://code.jquery.com/jquery-latest.js'></script>
<!--
<script src="https://code.angularjs.org/1.3.9/angular.min.js"></script>
<script src="https://code.angularjs.org/1.3.9/angular-route.js"></script>
-->
<style type='text/css'>
.empty {
color: red;
}
</style>
<script type='text/javascript'>
$(function(){
var o=$('#medal > div');
if (o.filter(':empty').length==o.length) {
$('#face').addClass('empty');
};
});
</script>
</head>
<body>
<div id="person">
<div id="face">Empty</div>
<div id="info"></div>
<div id="medal">
<div id="da"></div>
<div id="po"></div>
<div id="projects"></div>
<div id="opens"></div>
<div id="effect"></div>
<div id="potencial"></div>
</div>
</div>
</body>
</html>