I have a child element of a div named "bob" that's class is '.divTitle'

<div id="bob">
   <div class="divTitle">
      <a href="#">
         <h1>Title</h1>
      </a>
   </div>
</div>

I am trying to set the background color of "divTitle" to red but for the life of me can't get this to work. Right now I am trying two things...

$('#bob').children('.divTitle')[0].css('background-color', '#0f0'); // assuming children is returning an array...

and

$('#bob').children('.divTitle').css('background-color', '#0f0');

neither with any success... can anyone tell me what I am missing here? Do I have to go deeper than ".children"?