create buttonrenderer to set font and border color

i create new buttonrenderer 'NewButtonRenderer' for 'NewButton'
- [assembly: ExportRenderer(typeof(NewButton), typeof(NewButtonRenderer ))]
- public class NewButtonRenderer : ButtonRenderer
- protected override void OnElementChanged(ElementChangedEventArgs e)

i want to set background ,text color , border color, font style , font and width properties to new button 'NewButton' in android platform