Cannot change background-color property of nav element in CSS

nav {
  background-color: #CC3333;
  border: 5px solid red;
}

     <nav class="navbar navbar-default navbar-fixed-top">    
                <div class="container">
                    <button type="button" class="btn btn-default navbar-btn">About Me</button>
                    <button type="button" class="btn btn-default navbar-btn">Portfolio</button>
                    <button type="button" class="btn btn-default navbar-btn">Contact Me</button>
                </div>
            </nav>

I have no idea why it is not running, so any help would be much appreciated!