Activity indicator color

Is it possible to change the color of ActivityIndicator in Android?

The Color property seems to get ignored in 1.4.1 stable.

<ActivityIndicator x:Name="ActivitySearch"
                           Grid.Row="2"
                           Color="Black"
                           IsRunning="{Binding Busy}"
                           IsVisible="{Binding Busy}" />

Has anyone had any luck changing the color?

Also is it possible to style the alert dialog? i tried changing it in an Android style but it gets ignored.

<item name="android:alertDialogStyle">@style/v_alertDialogStyle</item>

<style name="v_alertDialogStyle" parent="@android:style/Theme.Dialog">
    <item name="android:background">@color/dialog_background</item>
    <item name="android:textColorPrimary">@color/dialog_textcolor</item>
  </style>

Thanks.