Código HTML:
<html><head>
<script src="http://code.jquery.com/jquery-latest.js"></script>
<script type="text/javascript">
$(document).ready(function(){
$('.brc').click( function(){
$(this).css('color', 'blue').siblings().css('color', 'red');
});
});
</script>
</head>
<body>
<div class="brc">1</div>
<div class="brc">2</div>
<div class="brc">3</div>
<div class="brc">4</div>
</body>
</html>