<link href="//maxcdn.bootstrapcdn.com/bootstrap/3.3.0/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//maxcdn.bootstrapcdn.com/bootstrap/3.3.0/js/bootstrap.min.js"></script>
<script src="//code.jquery.com/jquery-1.11.1.min.js"></script>
<div class="container">
<div class="row">
<div class="col-sm-5">
<div class="btn-group">
<button type="button" class="btn btn-default selected" disabled>
scegli un colore
</button>
<button type="button" class="btn btn-default dropdown-toggle" data-toggle="dropdown" aria-expanded="false">
<span class="caret"></span>
</button>
<ul id="color-list" class="dropdown-menu scrollable-menu" role="menu"></ul>
</div>
</div>
</div>
</div>