title: Change the background color of MaterialButtonToggleGroup
body: <p>I'm using MaterialButtonToggleGroup to create selector buttons.
  I want to change the background color of MaterialButton buttons. Its default color is light blue, and I want to change it to light green. Currently, I'm using drawable sectors to change the background color, but it is not working.</p>
  <p><strong>Default color</strong>,
  <a href="https://i.stack.imgur.com/rAufz.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/rAufz.jpg" alt="enter image description here" /></a></p>
  <p><strong>Want this color,</strong>
  <a href="https://i.stack.imgur.com/Twej9.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Twej9.jpg" alt="enter image description here" /></a></p>
  <p><strong>Here is my layout,</strong></p>
  <pre><code>&lt;com.google.android.material.button.MaterialButtonToggleGroup
      android:id=&quot;@+id/toggleContent&quot;
      android:layout_width=&quot;wrap_content&quot;
      android:layout_height=&quot;wrap_content&quot;
      app:checkedButton=&quot;@id/btnOutline&quot;
      app:layout_constraintBottom_toBottomOf=&quot;parent&quot;
      app:layout_constraintLeft_toLeftOf=&quot;parent&quot;
      android:visibility=&quot;visible&quot;
      app:layout_constraintRight_toRightOf=&quot;parent&quot;
      app:singleSelection=&quot;true&quot;&gt;
  
      &lt;com.google.android.material.button.MaterialButton
          android:id=&quot;@+id/btnOutline&quot;
          style=&quot;@style/Widget.MaterialComponents.Button.OutlinedButton&quot;
          android:layout_width=&quot;wrap_content&quot;
          android:layout_height=&quot;wrap_content&quot;
          android:background=&quot;@drawable/button_selector&quot;
          android:text=&quot;@string/outline&quot;
          android:textAllCaps=&quot;false&quot; /&gt;
  
      &lt;com.google.android.material.button.MaterialButton
          android:id=&quot;@+id/btnMain&quot;
          style=&quot;@style/Widget.MaterialComponents.Button.OutlinedButton&quot;
          android:background=&quot;@drawable/button_selector&quot;
          android:layout_width=&quot;wrap_content&quot;
          android:layout_height=&quot;wrap_content&quot;
          android:text=&quot;@string/main&quot;
          android:textAllCaps=&quot;false&quot; /&gt;
  
  &lt;/com.google.android.material.button.MaterialButtonToggleGroup&gt;
  </code></pre>
  <p><strong>Here is my drawable file &quot;button_selector&quot;,</strong></p>
  <pre><code>    &lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
  &lt;selector xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;&gt;
  
      &lt;item android:state_selected=&quot;true&quot; android:drawable=&quot;@drawable/selector_color&quot;/&gt;
  
  &lt;/selector&gt;
  </code></pre>
  <p><strong>Here is the &quot;selector_color&quot; file,</strong></p>
  <pre><code>  &lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
  &lt;shape xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;&gt;
  
      &lt;solid android:color=&quot;#93cdcb&quot;/&gt;
  &lt;/shape&gt;
  </code></pre>