title: Button labels stay greyed out after setEnabled(True)
body: <p>I want to disable and later re-enable a bunch of QPushButtons and QRadioButtons. Disabling them using <code>button.setEnabled(False)</code> works perfectly, the button outline and label are greyed out and it's not clickable anymore.</p>
  
  <p>However, after doing <code>button.setEnabled(True)</code> later, the outline returns from grey to white, but the label stays grey.</p>
  
  <p>Did I miss something or is this a bug in Qt?</p>