User16/DemoShelest/App.xaml

<Application x:Class="DemoShelest.App"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:local="clr-namespace:DemoShelest"
             StartupUri="MainWindow.xaml">
    <Application.Resources>
        <Style TargetType="TextBlock">
            <Setter Property="FontFamily" Value=" Monotype Corsiva" />
        </Style>
        <Style TargetType="StackPanel">
            <Setter Property="Background" Value="#C6D7FF"/>
        </Style>
        <Style TargetType="Button">
            <Setter Property="Background" Value="#46B29D"/>
        </Style>
    </Application.Resources>
</Application>