Remove searchbar background color inside a frame

Hello. I am trying to remove the grey background color in Ios but I can not find any solution. The background doesn't exist on Android.

    <Frame BackgroundColor="Transparent" Margin="13,10,13,0" Padding="0" BorderColor="Gray">
        <SearchBar Placeholder="Search" 
                    x:Name="searchBarChat"
                    HeightRequest="40"
                   FontSize="17"/>
    </Frame>