title: Highlight the background of the navigation menu item currently selected
body: <p>this is a snip/screenshot of my app design in Adobe Illustrator: <a href="https://imgur.com/a/7tXii" rel="noreferrer">https://imgur.com/a/7tXii</a>
  Depending on the menu you are currently in, the respective section shall be highlighted as shown below (light blue in this case).</p>
  
  <p>I know that you can change the ITEM/ICON color via a custom ThemeOverlay that you create under /styles.xml and by adding app:theme="@style/afore_mentioned_theme_overlay" like this:</p>
  
  <pre><code>    &lt;style name="ThemeOverlay.AppCompat.navTheme"&gt;
  
      &lt;!-- Color of text and icon when SELECTED --&gt;
      &lt;item name="colorPrimary"&gt;@color/color_of_your_choice&lt;/item&gt; 
  
      &lt;!-- Background color when SELECTED --&gt;
      &lt;item name="colorControlHighlight"&gt;@color/color_of_your_choice&lt;/item&gt; 
  
  &lt;/style&gt;
  </code></pre>
  
  <p>However, all this does is change the icon color upon selection, instead of highlighting the section below the icon. 
  The main problem is, probably, that the navigation background is a horizontal bar along the entire screen, but I just want to change the color of 33% of it, depending on the selected item. This will probably require a dirty workaround (?).</p>