title: PYQT Set different background color for every tab in QTabWidget
body: <p>I have a QTabWidget with a number of tabs
  I want to set the background color of each tab in the tabBar differently.</p>
  <p>I can set the text color using: tabBar().setTabTextColor(index, color)
  But i want to set the background not the text color.</p>
  <p>How can that be done?</p>