Tabbar Image not showing correctly

Hi all,
I have some code as follows:

        var home = new Home () {Title = "Play", Icon = "icon_play.png"};
        var learn = new Learn () { Title = "Learn", Icon = "icon_learn.png" };

        var MainPage = new TabbedPage{ Children = { home,learn } };

        return MainPage;

When i run the code on iOS I dont get to see my icons. All I see is blue circles like as if using one one channel of color. How can this be changed so it works correctly?

icon_play.png and icon_learn.png are in the resources folder and build action set up correctly. It runs fine but does not show any image.

Any ideas?