在我的应用程序中完全正常

import 'package:flutter_statusbarcolor/flutter_statusbarcolor.dart';

void main() => runApp(new MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    FlutterStatusbarcolor.setStatusBarColor(Colors.white);
    return MaterialApp(
      title: app_title,
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: HomePage(title: home_title),
    );
  }
}

（这个包）

UPD： 另一种解决方案

SystemChrome.setSystemUIOverlayStyle(SystemUiOverlayStyle(
  statusBarColor: Colors.white
));