Question

How do I get rid of that white background behind the image?

CSS:I thought webkit would do the trick but it’s not

 <style>
 .qq {
    background-image: url('../images/select-category.png');
    width: 148px;
    height:34px;
    -webkit-appearance: none;
  }
 </style>

HTML:

 <div style="float:left;">
      <form>
          <select id="basic" class="qq" onchange="showFolders(this.value)">
              <?php
                  foreach ($folder as $t)
                  {
                      echo '<option value="'.$t['folder_id'].'">'.$t['name'].'</option>';
                  }
              ?>  
          </select>
      </form>
  </div>

Answer 1

That white background is probably present in your image file select-category.png. To remove it, you will need to edit the image file itself.

If not, then it’s coming from somewhere else. Please provide a small self-contained example, which contains just enough code to demonstrate the problem, without anything extra. Post this code into the question, or in a JSFiddle (jsfiddle.net). Be sure that this example hast HTML (not PHP) and contains your image file.