Angular 5 and material - How to change the background color from SnackBar component

I have to change the background from the snackbar component. I'm using it to alert or inform the user about some either error or completed action the user did.

The material version from the project. "@angular/material": "^5.0.0-rc.1",

The documentation https://material.angular.io/components/snack-bar/api say about an api to change the class.

panelClass: string | string[] Extra CSS classes to be added to the snack bar container.

This is what I add in the css file.

.mycsssnackbartest {
  background-color: blue;
}

This is the code to open the snackbar

this.snackBar.open('Informing the user about sth', 'User Message' , {
    panelClass: ['mycsssnackbartest ']
} );

What am I doing wrong?

Angular < V15

You have to use the panelClass option (since v6) to apply classes on a snackbar like this:

this.snackBar.open(message, action, {
  duration: 2000,
  panelClass: ['blue-snackbar']
});

CSS (in global styles.scss):

.blue-snackbar {
  background: #2196F3;
}

See the Stackblitz example

Angular >= v15

The Angular team did add global css variable

So you still need to add the panelClass and you can add it to CSS like this

  .mat-mdc-snack-bar-container {
    &.blue-snackbar {
      --mdc-snackbar-container-color: #2196f3;
      --mat-mdc-snack-bar-button-color: #fff;
      --mdc-snackbar-supporting-text-color: #fff;
    }
  }