Answers for "flutter style"

flutter ui style

AnnotatedRegion<SystemUiOverlayStyle>(
      value: const SystemUiOverlayStyle(
        systemNavigationBarColor: Colors.red, // navigation bar color
        systemNavigationBarIconBrightness: Brightness.light, //navigation bar icons' color
      ),
      child: Scaffold(
        appBar: AppBar(
          backgroundColor: Colors.red,
          title: const Text('data'),
          systemOverlayStyle: SystemUiOverlayStyle.dark.copyWith(
            statusBarColor: Colors.red,
            statusBarIconBrightness: Brightness.light,
          ),
        ),
      ),
    )

how to use theme style and textstyle together in flutter text widget

Theme.of(context)
.textTheme.display1
.merge(TextStyle(color: Colors.red)