title: Change TopAppBar background color from themes.xml
body: <p>In Jetpack Compose, <strong>TopAppBar</strong> shows <code>default background color</code>  irrespective of what we added to <code>themes.xml</code>.</p>
  <p>So how can we change <strong><code>TopAppBar</code></strong> background color from <strong><code>themes.xml</code></strong> so it's applied globally to the App?</p>
  <pre><code>TopAppBar(
      title = { Text(&quot;Activity&quot;) },
      navigationIcon = {
          IconButton(onClick = { onBackPressed() }) {
              Icon(Icons.Filled.ArrowBack, contentDescription = null)
          }
      }
  )
  </code></pre>
  <p>themes.xml</p>
  <pre><code>&lt;style name=&quot;Theme.MyApplication&quot; parent=&quot;Theme.MaterialComponents.DayNight&quot;&gt;
          &lt;!-- Primary brand color. --&gt;
          &lt;item name=&quot;colorPrimary&quot;&gt;@android:color/black&lt;/item&gt;
          &lt;item name=&quot;colorPrimaryVariant&quot;&gt;@android:color/holo_orange_dark&lt;/item&gt;
          &lt;item name=&quot;colorOnPrimary&quot;&gt;@android:color/white&lt;/item&gt;
  &lt;/style&gt;
  </code></pre>
  <p><a href="https://i.stack.imgur.com/H2kWY.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/H2kWY.png" alt="enter image description here" /></a></p>
  <p>Note : we can change it through <code>backgroundColor</code> attribute of <code>TopAppBar</code> but here I want to achieve it globally.</p>