transparent doesn't work

I’m tryng to apply a transparent color to a nav, but its not work:

<div class="nav-wrapper transparent">
              <a href="#!" class="brand-logo"><img src="img/logo.png" class="square" width="10%;"> </a>
              <a href="#" data-activates="mobile-demo" class="button-collapse"><i class="material-icons">menu</i></a>
              <ul class="right hide-on-med-and-down">
                <li><a href="" class="green-text">A ONG</a></li>
                <li><a href="">Projetos</a></li>
                <li><a href="">Filie-se</a></li>
                <li><a href="">Media</a></li>
              </ul>
              <ul class="side-nav" id="mobile-demo">
                <li><a href="">A ONG</a></li>
                <li><a href="">Projetos</a></li>
                <li><a href="">Filie-se</a></li>
                <li><a href="">Media</a></li>
              </ul>
            </div>

[vicyork]

Why is this still broken? Hummm. @torreslucas13 did you ever figure it out?

[acburst]

You have to add the class to the nav:

<nav class="transparent">
<div class="nav-wrapper">
</div>
</nav>