jQuery make DRY two almost identical on click function
You need to have a group selector and just use this context to have the clicked list element:    

  $('ul.icons li.size, ul.icons li.color').click(function() {
      $(this).addClass('selected')      // add to clicked li
             .siblings('li')           // get all other lis
             .removeClass('selected');  // remove the class
   });