改变浮动操作按钮颤动的颜色

Changing Color of Floating Action Button Flutter

我想在按下浮动按钮时更改浮动按钮的颜色,但找不到解决方法,我该如何解决?提前致谢。

 var color1;
    var floatingActionButton1 = FloatingActionButton(
      onPressed: () {
        setState(() {
          simpleInterest.principal = double.parse(_principalController.text);
          color1 = Colors.green;
        });
      },
      elevation: 40,
      backgroundColor: color1,
      heroTag: "btn1",
      child: Icon(Icons.check),
    );

查看代码:

var isPressed = false;
.....
floatingActionButton: FloatingActionButton(
    child: Icon(Icons.check),
    backgroundColor: isPressed ? Colors.green : Colors.blue,
    onPressed: () => setState(() => isPressed = !isPressed),
  ),