How to change background color of Elevated Button in flutter

ElevatedButton(
            child: Text('Button'),
            onPressed: () {},
            style: ButtonStyle(
                backgroundColor: MaterialStateProperty.all(Colors.red),
                padding: MaterialStateProperty.all(EdgeInsets.all(50)),
                textStyle: MaterialStateProperty.all(TextStyle(fontSize: 30))),
),

ElevatedButton(
  style: ButtonStyle(
    backgroundColor: MaterialStateProperty.resolveWith<Color>(
      (Set<MaterialState> states) {
        if (states.contains(MaterialState.pressed))
          return Colors.green;
        return null; // Use the component's default.
      },
    ),
  ),
)

bool isButtonPressed = false;

RaisedButton(
            color: isButtonPressed ? Colors.green : Colors.red,
            onPressed: () {
              setState(() {
                isButtonPressed =!isButtonPressed;
              });
            },
          ),