title: Using QApplication::setStyleSheet to override QSS attributes set in Qt
body: <p>I created a button in <code>Qt</code> and gave it the <code>QSS</code> attribute <code>background-color: gray;</code>, while my external stylesheet has set the <code>QSS</code> attribute of the same button to <code>background-color: blue;</code>. When I run the application the button is gray, even though the style sheet is applied <em>after</em> the <code>QWidget::show()</code> is called and just before <code>QApplication::exec()</code>, as shown below:</p>
  
  <pre><code>MyWidget w;
  w.show();
  ...
  app.setStyleSheet("..."); // contents of external stylesheet
  return app.exec();    
  </code></pre>
  
  <p>Is it possible to have <code>QApplication::setStyleSheet()</code> override the <code>QSS</code> attributes assigned to a Widget in <code>Qt</code>.</p>