...
import Ionicons from 'react-native-vector-icons/Ionicons';

...

const RootTabs = TabNavigator({
  Home: {
    screen: HomeScreen,
    navigationOptions{
      tabBarLabel: 'Home'Box-sizing: inherit; color: rgb(88,
      tabBarIcon{ tintColorBox-sizing: inherit; color: rgb(88, focused }) => (
        <Ionicons name={focused ? 'ios-home' 'ios-home-outline'} size{26style{{ color: tintColor } />
      )Box-sizing: inherit; color: rgb(88,
    Box-sizing: inherit; color: rgb(88,
  Box-sizing: inherit; color: rgb(88,
  Profile: ProfileScreen'Profile''ios-person' 'ios-person-outline'Box-sizing: inherit; color: rgb(88,
;

export default RootTabs;