Adding back ground color to a post with html

Hi!
I would like to ad a color back ground to this.
I would like it to be the blue that the theme uses.
http://fisherynation.com/
Could someone take a peak and help me out?
Thank you. BH

<h4> U S Admiralty Law</h4>
<p> lafreniere.com</p>
<p><img alt=”” src=”http://media.merchantcircle.com/3344860/american-flag-2a_full.jpeg&#8221; width=”158″ height=”94″ /></p>