title: Can't change tabbar label's color
body: <p>I'm trying to change my active tab title color, I tried using tabBarOptions but It just won't work, what am I doing wrong?
  This is my code:</p>
  
  <pre><code>  Home:{
  screen: TabNavigator({
    Home: {
      screen: HomeScreen,
      navigationOptions: ({ navigation }) =&gt; ({
        title: 'Home',
        tabBarIcon: ({ tintColor, focused }) =&gt; (
          &lt;Ionicons
          name={focused ? 'ios-home' : 'ios-home-outline'}
          size={26}
          style={{ color: focused ? `${tabBarColor}` : tintColor}}
          /&gt;
        ),
        header: null,
      }),
    },
    Profile: {
      screen: ProfileScreen,
      navigationOptions: ({ navigation }) =&gt; ({
        title: 'Profile',
        tabBarIcon: ({ tintColor, focused }) =&gt; (
          &lt;Ionicons
          name={focused ? 'ios-people' : 'ios-people-outline'}
          size={26}
          style={{ color: focused ? `${tabBarColor}` : tintColor }}
          /&gt;
        ),
        header: null,
      }),
    },
  }),
  tabBarOptions:{
    activeTintColor: `${tabBarColor}`,
  }
  }
  </code></pre>
  
  <p>I read I the documentation and searched for examples but couldn't find anything that worked for me.
  It's like the app is just ignoring the tabBarOptions.</p>
  
  <p>Thanks in advance!</p>