Change Navigation bar color in a FreshNavigationContainer (FreshMVVM)

Hello,

I am using FreshMVVM and in my case the FreshNavigationContainer with a general MasterDetailPage described from Michael Ridland like here : https://github.com/rid00z/FreshMvvm

MainMasterDetailPage = new MasterDetailPage(); //generic master detail page

//we setup the first navigation container with ContactList
var menuPage = FreshPageModelResolver.ResolvePageModel<MasterMenuPageModel>();
menuPage.Title = "Menü";

//we setup the first navigation container with name MasterPageArea
var masterPageArea = new FreshNavigationContainer(menuPage, "MasterPageArea");
masterPageArea.Title = "Menu";
masterPageArea.Icon = "Menu.png";
masterPageArea.BackgroundColor = Color.Red;

BUT: The Navigation bar color ALWAYS stays white !!!!

Any idea to change the color of the Navigation bar in a FreshNavigationContainer ?

Best

Marco