title: Trouble with changing the placeholder color of md-select
body: <p>I've tried to change the placeholder color of md-select, but it's not working:</p>
  
  <p><strong>CSS</strong></p>
  
  <pre><code>md-select::-webkit-input-placeholder {
    color: white;}
  </code></pre>
  
  <p><strong>HTML</strong></p>
  
  <pre><code>&lt;md-select ng-model="weapon" placeholder="Navaneethan@gmail.com" class="md-no-underline" style="margin-top:5px"&gt;
    &lt;md-option value="axe"&gt;option1&lt;/md-option&gt;
    &lt;md-option value="axe"&gt;option2&lt;/md-option&gt;
  &lt;/md-select&gt;
  </code></pre>
  
  
  
  <p>Help me to change the color of the placeholder</p>