Simple Custom Renderer of Searchbar - Android

I have a Searchar Control. On my Galaxy s4 it's with a grey background color. On the nexus it has a white background color.
Do I need a custom renderer?

For now I have:

public class StyledSearchbar : SearchBar
    {
        public Color farbe { get; set; }
    }

this simple searchbar:

StyledSearchbar searchBar = new StyledSearchbar
            {
                Placeholder = "Suche",
                Scale = 0.9,
                //HorizontalOptions = LayoutOptions.FillAndExpand,
                WidthRequest = 310,
            };

and my custom renderer:

[assembly: ExportRenderer(typeof(StyledSearchbar), typeof(StyledSearchBarRenderer))]

namespace ZF.Droid
{
    class StyledSearchBarRenderer : SearchBarRenderer {
        protected override void OnElementChanged(ElementChangedEventArgs<SearchBar> e)
        {
            base.OnElementChanged(e);
            var styledSearchbar = (StyledSearchbar)Element;
            styledSearchbar.BackgroundColor = Xamarin.Forms.Color.Red;
           }
    }   
    }