import ThemeProvider, { applyTheme } from 'react-native-theme-provider';

<ThemeProvider
  themes={{
    'default': {
      color: '#333333',
    },
    'red': {
      color: 'red',
    },
  }}   {/* you can use require('/path/to/your/themefile') also, import is not support current. */}

  onChange={(name, before, after) => {
    console.log(before)
    console.log(after)
    // persist new theme into redux or something else.
    // this module will persist theme key into localstorage defaultly that key named `@App:theme`
  }}   {/* listen changes while theme changed */}
>
  <App />
</ThemeProvider>

@applyTheme()
class App extends Component {
  render() {
    return (
      <View style={styles.container}>
        <Text style={styles.welcome}>
          Welcome to React Native!
        </Text>
        <Text style={styles.instructions}>
          To get started, edit App.js
        </Text>
        {/* this.props.theme.styles is the theme styles object passed by yourself in ThemeProvider Component */}
        <Text style={[styles.instructions, this.props.theme.styles]}>
          {instructions}
        </Text>
        <Button
          title="Toggle Theme"
          onPress={() => {
            this.props.activeTheme(this.props.theme.current === 'default' ? 'red' : 'default');
          }}
        />
      </View>
    );
  }
}