article_colors_block7.xml

<style name="Widget.MyApp.Button">
    <item name="android:textColor">?attr/colorOnPrimary</item>
    <item name="backgroundTint">?attr/colorPrimary</item>
  </style>

  <Button
    style="@style/Widget.MyApp.Button"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
  />