title: Want to make border color red when input is invalid
body: <p>I now have a text appear that says the input is invalid, but I would like to make the border red instead of displaying this text, because it looks pretty sloppy. I wondered how I can do this, can't seem to find a right solution online.</p>
  
  <p>This is the code at the moment: </p>
  
  <pre><code> &lt;input placeholder="Vraag" formControlName="actualQuestion" type="text" class="form-control"&gt;
                          &lt;div class="text-danger" *ngIf="isSubmitted &amp;&amp; formControls.actualQuestion.errors?.required"&gt; This field is required. &lt;/div&gt;
                          &lt;input placeholder="Optie 1" formControlName="option1" type="text" class="form-control"&gt;
                          &lt;div class="text-danger" *ngIf="isSubmitted &amp;&amp; formControls.option1.errors?.required"&gt; This field is required. &lt;/div&gt;
                          &lt;input placeholder="Optie 2" formControlName="option2" type="text" class="form-control"&gt;
                          &lt;div class="text-danger" *ngIf="isSubmitted &amp;&amp; formControls.option2.errors?.required"&gt; This field is required. &lt;/div&gt;
  </code></pre>
  
  <p>I uploaded an image with a drawn border around "Optie 1" to clarify what I mean.
  <a href="https://i.stack.imgur.com/86Vs7.png" rel="noreferrer"><img src="https://i.stack.imgur.com/86Vs7.png" alt="enter image description here"></a></p>