title: Setting only background color of MainWindow Qt
body: <p>So I am trying to change only the background color of my <code>MainWindow</code>. When I try to do this using <code>this-&gt;setStyleSheet("background-color:black;");</code> for example it changes the background of everything: child widgets, <code>QTextBoxEdit</code> background, everything.</p>
  
  <p>Is there a way to only change the background of just the main window?</p>