Xamarin Forms - Android - Override textAppearance of Small , Medium , Large

Hey guys ,

i'm trying to override the default text appearance in my xamarin forms app for android .

This is my styles.xml but its not working ( For textView , picker etc...)

<?xml version="1.0" encoding="UTF-8"?>
<resources>

  <style name="newTheme" parent="newTheme.Base"></style>

  <style name="newTheme.Base" parent="Theme.AppCompat.Light.NoActionBar">

    <item name="colorPrimary">@color/primary</item>
    <item name="colorPrimaryDark">@color/primaryDark</item>
    <item name="colorAccent">@color/accent</item>

  </style>

  <style name="TextAppearance.Large" parent="newTheme">
    <item name="android:textSize">11sp</item>
  </style>

  <style name="TextAppearance.Medium" parent="newTheme">
    <item name="android:textSize">11sp</item>
  </style>

  <style name="TextAppearance.Small" parent="newTheme">
    <item name="android:textSize">11sp</item>
  </style>


</resources>