Use case

The background color for SnackBarAction should be allowed to change when SnackBarAction.textColor is set to some custom color.

For example, in below code, I have set textColor to Colors.green, and I want the background color (blue in the image) to be set to green with some alpha value.

ScaffoldMessenger.of(context).showSnackBar(
  SnackBar(
    content: const Text('Awesome Snackbar!'),
    action: SnackBarAction(
      label: 'Action',
      onPressed: () {
        // Code to execute.
      },
      textColor: Colors.green,
    ),
  ),
);

Proposal

I can think of 2 options:

1. Add a parameter to SnackBarAction which can be used to set the background color.
2. When SnackBarAction.textColor is set, then set the background color to some alpha value of this textColor.