title: Qt Gui Application background color stylesheet
body: <p>I want to set background color for my form</p>
  
  <p>like this</p>
  
  <pre><code>body
  {
    background-color: #fff;
  }
  </code></pre>
  
  <p>I am using QWidget selector but i only want to change window background;</p>
  
  <p>And how i can ise one stylesheet for all windows?</p>