Problem with animate elements with for loop using next()

Problem with animate elements with for loop using next()

I want to change background-color (whatever) for each of test_div when test_div_main is clicked. I want to do this in loop because in future i want to set color depended on i value in to loop.
This is clear html code:
  1.     <div class="test_div_main">1</div>
  2.     <div class="test_div">2</div>
  3.     <div class="test_div">3</div>
  4.     <div class="test_div">4</div>
  5.     <div class="test_div">5</div>
  6.     <div class="test_div">6</div>
  7.     <div class="test_div">7</div>
and this is jQ code:
  1. $(document).ready(function(){
  2.     var numItems = $('.test_div').length;
  3.     $('.test_div_main').click(function(){
  4.         var next_div = $('.test_div_main').next('.test_div');
  5.         for (var i = 0; i > numItems; i++)
  6.         {
  7.             next_div.css({
  8.                "background-color": "yellow" 
  9.             });
  10.             next_div = next_div.next('.test_div')
  11.         }
  12.     });
  13. });
Can You find reason why it's not working? Or maybe there is better way than mine?