title: Angular 6 Material retreive material colors
body: <p>"@angular/material": "^6.2.1"
  Got quite stuck with a very minor issue.
  Can't import any standard material color in any of my app's css/scss files, including <code>styles.scss</code></p>
  
  <p>example:</p>
  
  <p><code>$app-panel-green: mat-color($mat-green);</code></p>
  
  <p>gives this error in any scss file:</p>
  
  <pre><code>ERROR in ./src/styles.scss (./node_modules/raw-loader!./node_modules/postcss-loader/lib??embedded!./node_modules/sass-loader/lib/loader.js??ref--14-3!./src/styles.scss)
  Module build failed: 
  $app-panel-green: mat-color($mat-green);
                             ^
        Undefined variable: "$mat-green".
        in /**********/src/styles.scss (line 1, column 29)
  </code></pre>
  
  <p>styles.scss consits only of (except previous):</p>
  
  <pre><code>@import "~@angular/material/prebuilt-themes/deeppurple-amber.css";
  /*@import './theme.scss';*/
  
  body { margin: 0; }
  </code></pre>
  
  <p>and pre-built theme works just fine. 
  I don't even need a custom theme, just want to use material color palette.</p>