title: Setting activeTintColor on a custom drawer
body: <p>I am creating a drawer using DrawerNavigator. I was highlighting the current selected screen on the drawer by setting a activeTintColor value</p>
  
  <pre><code>contentOptions: {
        activeTintColor: '#65433d',
      }
  </code></pre>
  
  <p>Now I decided to customize my drawer by setting a contentComponent. So looks my code like </p>
  
  <pre><code>export default DrawerNavigator({
    Page1: {
      screen: Page1
    },
    Page2: {
      screen: Page2
    },
    Page3: {
      screen: Page3
    }
  }, {
    contentComponent: SideMenu,
    drawerWidth: 300
  });
  </code></pre>
  
  <p>In SlideMenu.js</p>
  
  <pre><code>/**
   * Sample React Native App
   * https://github.com/facebook/react-native
   * @flow
   */
  
  import PropTypes from 'prop-types';
  import React, {Component} from 'react';
  import styles from './SideMenu.style';
  import {NavigationActions} from 'react-navigation';
  import {ScrollView, Text, View} from 'react-native';
  
  class SideMenu extends Component {
    navigateToScreen = (route) =&gt; () =&gt; {
      const navigateAction = NavigationActions.navigate({
        routeName: route
      });
      this.props.navigation.dispatch(navigateAction);
    }
  
    render () {
      return (
        &lt;View style={styles.container}&gt;
          &lt;ScrollView&gt;
            &lt;View&gt;
              &lt;Text style={styles.sectionHeadingStyle}&gt;
                Section 1
              &lt;/Text&gt;
              &lt;View style={styles.navSectionStyle}&gt;
                &lt;Text style={styles.navItemStyle} onPress={this.navigateToScreen('Page1')}&gt;
                Page1
                &lt;/Text&gt;
              &lt;/View&gt;
            &lt;/View&gt;
            &lt;View&gt;
              &lt;Text style={styles.sectionHeadingStyle}&gt;
                Section 2
              &lt;/Text&gt;
              &lt;View style={styles.navSectionStyle}&gt;
                &lt;Text style={styles.navItemStyle} onPress={this.navigateToScreen('Page2')}&gt;
                  Page2
                &lt;/Text&gt;
                &lt;Text style={styles.navItemStyle} onPress={this.navigateToScreen('Page3')}&gt;
                  Page3
                &lt;/Text&gt;
              &lt;/View&gt;
            &lt;/View&gt;
          &lt;/ScrollView&gt;
          &lt;View style={styles.footerContainer}&gt;
            &lt;Text&gt;This is my fixed footer&lt;/Text&gt;
          &lt;/View&gt;
        &lt;/View&gt;
      );
    }
  }
  
  SideMenu.propTypes = {
    navigation: PropTypes.object
  };
  
  export default SideMenu;
  </code></pre>
  
  <p>How can I set a different color for the selected menu item?</p>