graph/src/material.scss

@use '@angular/material' as mat;
@import '@angular/material/theming';
@include mat.core();
$my-app-primary: mat.define-palette(mat.$blue-grey-palette);
$my-app-accent:  mat.define-palette(mat.$green-palette);
$my-app-warn:    mat.define-palette(mat.$deep-orange-palette);

$my-app-theme: mat.define-light-theme($my-app-primary, $my-app-accent, $my-app-warn);

@include mat.all-component-themes($my-app-theme);

.mat-option:hover:not(.mat-option-disabled), .mat-option:focus:not(.mat-option-disabled), .mat-option.mat-active:not(.mat-option-disabled) {
  background-color: #F8CBBB;
}