You can target that div from your stylesheet in a number of ways.
Simply use
.col-md-6:first-child {
background-color: blue;
}
Another way is to assign a class to one div and then apply the style to that class.
<div class="col-md-6 blue"></div>
.blue {
background-color: blue;
}
There are also inline styles.
<div class="col-md-6" style="background-color: blue"></div>
Your example code works fine to me. I'm not sure if I undestand what you intend to do, but if you want a blue background on the second div just remove the bg-primary
class from the section and add you custom class to the div.
.blue {_x000D_
background-color: blue;_x000D_
}
_x000D_
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet"/>_x000D_
_x000D_
<section id="about">_x000D_
<div class="container">_x000D_
<div class="row">_x000D_
<!-- Columns are always 50% wide, on mobile and desktop -->_x000D_
<div class="col-xs-6">_x000D_
<h2 class="section-heading text-center">Title</h2>_x000D_
<p class="text-faded text-center">.col-md-6</p>_x000D_
</div>_x000D_
<div class="col-xs-6 blue">_x000D_
<h2 class="section-heading text-center">Title</h2>_x000D_
<p class="text-faded text-center">.col-md-6</p>_x000D_
</div>_x000D_
</div>_x000D_
</div>_x000D_
</section>
_x000D_