yoga/csharp/Facebook.Yoga.App/Facebook.Yoga.Universal.App/App.xaml

<Application
    x:Class="Facebook.Yoga.App.App"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:Facebook.Yoga.App"
    RequestedTheme="Light">

</Application>