title: Setting background color for header of Angular Material Card
body: <p><a href="https://material.angular.io/components/card/overview" rel="nofollow noreferrer">They are using it throughout the documentation</a> but I cannot find how to do add color to the header myself. <a href="https://i.stack.imgur.com/ObPDt.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ObPDt.jpg" alt="pale gray header screenshot"></a></p>
  
  <p>I assume there is a way to get a full bleed colored header without having to remove the padding from the card. <code>mat-card-title-group</code> also stays inside of the cards padding.</p>
  
  <pre><code>&lt;mat-card&gt;
      &lt;mat-card-title&gt;Notes&lt;/mat-card-title&gt;
      &lt;mat-card-content&gt;
          ...
      &lt;/mat-card-content&gt;
  &lt;/mat-card&gt;
  </code></pre>
  
  <p>Is there another component I should be looking at instead?</p>
  
  <p><em>ps: I found questions in regard to the original angular material for angular 1 but did not find anything for 2+.</em> </p>