How can I position Position MatSnackBar module in Angular?

You can determine the verticalPosition: MatSnackBarVerticalPosition as specified by the docs

ts:

openSnackBar(message: string, action: string) {
    this.snackBar.open(message, action, {
      duration: 2000,
      // here specify the position
      verticalPosition: 'top'
    });
}

Demo

To position the snackbar use position values

            this.snackBar.open(message.text, action, {
                duration: this.timeOut,
                verticalPosition: 'bottom', // 'top' | 'bottom'
                horizontalPosition: 'end', //'start' | 'center' | 'end' | 'left' | 'right'
                panelClass: ['red-snackbar'],
            });

and to change color, in your style.css define the red-snackbar:

 .red-snackbar{
  background-color: rgb(153, 50, 50);
  color:lightgoldenrodyellow;
}

https://www.coditty.com/code/angular-material-display-multiple-snackbars-messages-in-sequence