title: How to change default background color of callout bubble with detailCalloutAccessoryView
body: <p>In my app I have the following sutuation.</p>
  
  <p>I've implemented a custom callout bubble with custom detailCalloutAccessoryView with two labels inside.</p>
  
  <p>I know how to change the color of detailCalloutAccessoryView with this line. </p>
  
  <pre><code>view.detailCalloutAccessoryView?.backgroundColor = UIColor.red
  </code></pre>
  
  <p>But I can't figure out how to change background color of the main bubble (it is transparent grey/white now). With  <code>view.detailCalloutAccessoryView?.backgroundColor = UIColor.red</code>  line my calloutbubble looks like this:</p>
  
  <p><a href="https://i.stack.imgur.com/nHpAw.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/nHpAw.png" alt="enter image description here"></a></p>
  
  <p>But I want my custom bubble to look like this:</p>
  
  <p><a href="https://i.stack.imgur.com/fpQaQ.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/fpQaQ.png" alt="enter image description here"></a></p>
  
  <p>Here is my viewFor annotation method:</p>
  
  <pre><code> func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -&gt; MKAnnotationView? {
  
          if annotation is MKUserLocation {
              return nil
          }
  
          let identifier = "pin"
          var view : MKAnnotationView
  
          if let dequedView = mapView.dequeueReusableAnnotationView(withIdentifier: identifier) {
              dequedView.annotation = annotation
  
              view = dequedView
  
          } else {
              view = MKAnnotationView(annotation: annotation, reuseIdentifier: identifier)
  
              view.canShowCallout = true
  
          }
  
               let pinImage = UIImage.init(named: "customPin")
  
  
          DispatchQueue.main.async(execute: {
  
              view.detailCalloutAccessoryView?.backgroundColor = UIColor.red
  
          })
  
          view.image = pinImage
  
          configureDetailView(annotationView: view)
          return view
      }
  </code></pre>
  
  <p>I'm working in Xcode 8 w/ Swift 3.</p>
  
  <p>It would be also interesting to know how to change font type and default black color of the title from black to another color.
  In detail view i can easily change color of my custom labels in xib file but don't know how to access default title properties.</p>