title: MKMapView set style to black and white
body: <p>i'm trying to change the color scheme of the MKMapView to black and white. It's discussed in this topic: <a href="https://stackoverflow.com/questions/8989208/black-and-white-overlay-for-an-mkmapview">Black and white overlay for an MKMapView</a> but i have no clue how to achieve this.</p>
  
  <p>Can somebody help me out?</p>
  
  <p>Best regards,
  Lukas</p>