List

<fine-list id='myList1' 
  config='{
    "theme": "blue",
    "maxHeight": "300px",
    "datasource": {
      "transport": {
        "read": {
          "url": "../../includes/getList.php",
          "type": "json"
        }
      },
      "serverFiltering": false
    }
  }'>
</fine-list>

<select class="form-control" onchange="changeTheme(this);">
  <option>default</option>
  <option>flat</option>
  <option>dark</option>
</select>

<script type="text/javascript">
  function changeTheme(select) {
    var el = document.getElementById('myList1');
    var theme = select.selectedOptions[0].textContent;
    el.set('theme', theme);
  }    
</script>