Change ion-view header title

ionic-v1
1

Hi guys!

I have this:

<ion-view view-title="CLIENTES">

  <ion-nav-buttons side="right">
    <button class="button button-icon button-clear ion-plus-round" ng-click=""></button>
  </ion-nav-buttons>

  <ion-content>
    <h1>CLIENTES</h1>
  </ion-content>
</ion-view>

And all i want is apply the css class dark in the header.
How can i do that?
Thanks!!