Flutter - How to change TextField hint color?

I'm a bit confused how to change the hint color of the textfield. Someone can guide me how to do it.Thanks

child: TextField(
   style: TextStyle(fontSize: 20),
   decoration: InputDecoration(
                  hintText: "Password",
                  border: new OutlineInputBorder(
                            borderSide: new BorderSide(
                              color: Colors.teal,
                            ),
                          ),
                   prefixIcon: const Icon(
                            Icons.security,
                            color: Colors.white,
                          ),
                ),
   ),

Solution 1:

You can do with hintStyle: in InputDecoration

TextField(
        style: TextStyle(fontSize: 20),
        decoration: InputDecoration(
          hintText: "Password",
          hintStyle: TextStyle(fontSize: 20.0, color: Colors.redAccent),
          border: OutlineInputBorder(
            borderSide: BorderSide(
              color: Colors.teal,
            ),
          ),
          prefixIcon: const Icon(
            Icons.security,
            color: Colors.white,
          ),
        ),
      ),

Solution 2:

As an addition to the accepted answer, to update the focused hint decoration you have to update the app's Theme.

@override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
          primaryColor: Colors.white,
          inputDecorationTheme: const InputDecorationTheme(
            labelStyle: TextStyle(color: Colors.black),
            hintStyle: TextStyle(color: Colors.grey),
          )),
      home: MainScreen(),
    );
  }

Solution 3:

change both hintStyle and labelStyle

TextFormField(
              decoration: InputDecoration(
                hintText: '[email protected]',
                labelText: 'Email',
               hintStyle: TextStyle(color: Colors.white), # change to your color
                labelStyle: TextStyle(color: Colors.white), # change color
             ))