title: DrawerNavigator: Change Text Color
body: <p>On <code>react-navigation</code>'s <code>DrawerNavigator</code>, is there a way to change the text color and background color for the item?</p>
  
  <p>By default, the color scheme looks like the following:
  <a href="https://i.stack.imgur.com/3fv57.png" rel="noreferrer"><img src="https://i.stack.imgur.com/3fv57.png" alt="react-navigation color"></a></p>
  
  <p>Which is initialized by the following:</p>
  
  <pre><code>export const Drawer = DrawerNavigator({
      dOne: {
        screen: Screen1,
      },
      dTwo: {
        screen: Screen2,
      }
    }
  );
  </code></pre>
  
  <p>Setting the <code>color</code> property within the screen's <code>contentOptions</code>'s <code>style</code> does not appear to have an effect.</p>
  
  <p>Should I extend new components for each row (labeled "Primary", "Secondary", etc. right now)? or is there an easier way to stylize the existing implementation of the rows?</p>