title: How Can I customize mat-form-field in disabled state
body: <p>I am trying to customize the angular material mat-form-field :
  I was able to customize the underline border using :</p>
  
  <pre><code>::ng-deep.mat-form-field-ripple {
    background-color: yellow;
  }
  </code></pre>
  
  <p>now I am trying to customize the underline border in the disabled state to be solid instead of the dashed line :</p>
  
  <p>I tried this but it didn't work for underline :</p>
  
  <pre><code>::ng-deep.mat-form-field-disabled
   {
  
   }
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/61DI7.png" rel="noreferrer"><img src="https://i.stack.imgur.com/61DI7.png" alt="enter image description here"></a></p>
  
  <p>I want this to be gray solid in disabled state</p>
  
  <pre><code> &lt;mat-form-field&gt;
      &lt;input matInput placeholder="Input" [disabled]='true'&gt;
    &lt;/mat-form-field&gt;
  </code></pre>