title: ng-class add depending on group date data
body: <p>I have some data in an array name with <strong>$scope.data</strong> variable.</p>
  
  <pre><code>[
   {date:'02-05-2016'},
   {date:'02-05-2016'},
   {date:'04-05-2016'},
   {date:'04-05-2016'},
   {date:'05-05-2016'},
   {date:'05-05-2016'},
   ...
   ...
  ]
  </code></pre>
  
  <p>I have 2 css class (color1,color2). I want to add class in ng-repeat of each date group like</p>
  
  <pre><code>02-05-2016 =&gt; color1
  04-05-2016 =&gt; color2
  05-05-2016 =&gt; color1
  ...
  ...
  </code></pre>
  
  <p>I can't figure out how it will be in <strong>ng-repeat</strong></p>