CommandBar color in UWP

Question

I have a Xamarin project with UWP and need to set background color of Top Command Bar in UWP. I tried adding following in App.xaml in Shared Project (this gives error):

<Style TargetType="CommandBar">
      <Setter Property="Background" Value="#F44336" />                 
</Style>

I also tried adding following in App.xaml in UWP project:

<Application.Resources>
    <ResourceDictionary>
        <Style TargetType="AppBar">
            <Setter Property="Background" Value="#F44336"/>               
        </Style>
    </ResourceDictionary>        
</Application.Resources>

Nothing notable change happened. Can anyone please help?