AngularJS ng-click and ng-class.

HTML

<div ng-app="myApp" ng-controller="MainCtrl">
    <div ng-init="index=0; classes=['red', 'green']" ng-click="index = index + 1" ng-class="classes[index % classes.length]">Test 1 2 3.</div>
</div>

CSS

.red {
    background-color: red;
}

.green {
    background-color: green;
}

.blue {
    background-color: blue;
}

JavaScript

var app = angular.module('myApp', []);

app.controller('MainCtrl', function($scope) {});