unknown function 27mat palette 27

1There is another way to define it for Angular 8+
2
3Needed imports: 
4@import '~@angular/material/theming';
5@use '~@angular/material' as mat;
6@include mat.core();
7
8To define a palette:
9old way: $candy-app-warn:    mat-palette($mat-red);
10new way: $candy-app-warn:    mat.define-palette(mat.$red-palette);
11
12More detailed here: https://material.angular.io/guide/theming