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

app.controller('MainCtrl', function($scope, $http) {
  $scope.tags = [
    { text: 'Tag1' },
    { text: 'Tag2' },
    { text: 'Tag3' }
  ];
   
  $scope.loadTags = function(query) {
    return $http.get('tags.json');
  };
});
<!DOCTYPE html>
<html ng-app="plunker">

  <head>
    <meta charset="utf-8" />
    <title>AngularJS Plunker</title>
    <script>document.write('<base href="' + document.location + '" />');</script>
    <link rel="stylesheet" href="style.css" />
    <link rel="stylesheet" href="http://mbenford.github.io/ngTagsInput/css/ng-tags-input.min.css" />
    <script src="https://code.angularjs.org/1.4.2/angular.js"></script>
    <script src="http://mbenford.github.io/ngTagsInput/js/ng-tags-input.min.js"></script>
    <script src="app.js"></script>
  </head>

  <body ng-controller="MainCtrl">
    <tags-input ng-model="tags">
      <auto-complete source="loadTags($query)" 
                     match-class="{even: $index % 2 == 0, odd: $index % 2 != 0}"></auto-complete>
    </tags-input>
  </body>

</html>
.odd, .odd em {
  background: rgba(210,255,82,1) !important;
}

.even, .even em {
  background: rgba(241,231,103,1) !important;
}

.odd.selected, .even.selected, .odd.selected em, .even.selected em {
  background: red !important;
}
[
  { "text": "Tag1" },
  { "text": "Tag2" },
  { "text": "Tag3" },
  { "text": "Tag4" },
  { "text": "Tag5" },
  { "text": "Tag6" },
  { "text": "Tag7" },
  { "text": "Tag8" },
  { "text": "Tag9" },
  { "text": "Tag10" }
]