Change app background color in React Native

I’ve solved my problem, it was caused by StackNavigator. To solve it , just add some extra options

const HomeStack = StackNavigator(
      {
        Home: {
          screen: HomeScreen,
        },
        Item: {
          screen: ItemScreen,
          navigationOptions: ({ navigation }) => ({
            title: `${navigation.state.params.title}`,
          }),
        },
      },
      **
      {
        headerMode: 'screen',
        cardStyle: { backgroundColor: '#FFFFFF' },
      },
      **
    );