Angular 2 Material theme refer to color in SCSS

I've created a custom theme with the official guide.

@import '../node_modules/@angular/material/core/theming/_all-theme';
@include mat-core();

$primary: mat-palette($mat-teal);
$accent: mat-palette($mat-deep-orange);
$warn: mat-palette($mat-amber);

$theme: mat-light-theme($primary, $accent, $warn);

@include angular-material-theme($theme);

It actually does work. I can set the color of a md-toolbar or md-button with $primary. But I can't access the color variables within a SCSS of a component.

:host {
  .mat-grid-tile-header {
    background-color: $primary;
  }
}

Error in Webstorm:

"Element 'primary' is resolved only by name without using of explicit imports"

Error after build failed: "Undefined variable"

Okey, I somehow have to import it. But I don't get how.

I've tried importing the theme:

@import "../../../theme.scss";
    :host {
      .mat-grid-tile-header {
        background-color: $primary;
      }
    }

The error in Webstorm has gone away, but a new error after the build appeared:

Module build failed: 
undefined
            ^
      (50: #e0f2f1, 100: #b2dfdb, 200: #80cbc4, 300: #4db6ac, 400: #26a69a, 500: #009688, 600: #00897b, 700: #00796b, 800: #00695c, 900: #004d40, A100: #a7ffeb, A200: #64ffda, A400: #1de9b6, A700: #00bfa5, contrast: (50: rgba(0, 0, 0, 0.87), 100: rgba(0, 0, 0, 0.87), 200: rgba(0, 0, 0, 0.87), 300: rgba(0, 0, 0, 0.87), 400: rgba(0, 0, 0, 0.87), 500: white, 600: white, 700: white, 800: rgba(255, 255, 255, 0.87), 900: rgba(255, 255, 255, 0.87), A100: rgba(0, 0, 0, 0.87), A200: rgba(0, 0, 0, 0.87), A400: rgba(0, 0, 0, 0.87), A700: rgba(0, 0, 0, 0.87)), default: #009688, lighter: #b2dfdb, darker: #00796b, default-contrast: white, lighter-contrast: rgba(0, 0, 0, 0.87), darker-contrast: white, "50-contrast": rgba(0, 0, 0, 0.87), "100-contrast": rgba(0, 0, 0, 0.87), "200-contrast": rgba(0, 0, 0, 0.87), "300-contrast": rgba(0, 0, 0, 0.87), "400-contrast": rgba(0, 0, 0, 0.87), "500-contrast": white, "600-contrast": white, "700-contrast": white, "800-contrast": rgba(255, 255, 255, 0.87), "900-contrast": rgba(255, 255, 255, 0.87), "A100-contrast": rgba(0, 0, 0, 0.87), "A200-contrast": rgba(0, 0, 0, 0.87), "A400-contrast": rgba(0, 0, 0, 0.87), "A700-contrast": rgba(0, 0, 0, 0.87), "contrast-contrast": null) isn't a valid CSS value.

Does someone know how to solve this problem? Thanks in advance!

You'll want to use the mat-color($primary) function from @angular/material/core/theming/_theming.scss. That takes in the palette and returns the color.