title: How to style a Child html element in typescript / angular
body: <p>i am using ionic 3 to build a hybrid mobile app, one of the requirements is that the user have the ability to change the toolbar color dynamically. after the page is rendered that's how the html looks like:</p>
  
  <p><code>&lt;div id="divICanControl"&gt; //this div i can control
    &lt;div&gt; //but this one is generated by the framework and this is the div that change the background color of the toolbar
    &lt;/div&gt;
  &lt;/div&gt;</code></p>
  
  <p>i tried to do the following:
  <code>document.getElementById('divICanControl').childNodes[0].style.backgroundColor = this.someColor;</code></p>
  
  <p>it worked occasionally but it created the following error in vscode:
  <code>[ts] Property 'style' does not exist on type 'Node'.</code></p>
  
  <p>and it stopped the build of the app.</p>
  
  <p>i am now searching for the right way to manipulate the dom using angular.</p>
  
  <p>thank you for your help and please keep in mind that i am new to angular 5 and typescript.</p>