Edit in JSFiddle

var myModule = angular.module('myModule', ['ngAnimate']);

<div ng-app="myModule" ng-init="addNewClass=false">
  <button ng-click="addNewClass=!addNewClass">Toggle Class</button>
  <div ng-class="{addNewClass:addNewClass}" class="my-toggle-animation">
    Lorem ipsum dolor sit amet, consectetur adipiscing elit...
  </div>
</div>

.my-toggle-animation {
  -webkit-transition:0.5s linear all;
  transition:0.5s linear all;
  background:white;
  padding:10px;
  border:1px solid black;
  color:black;
}
.my-toggle-animation.addNewClass {
  background: #5b86c7;
  color:#fff;
  border-color:#496ca0;
}