HelloWorld/Eight/App.xaml

<Application x:Class="Eight.App"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:local="clr-namespace:Eight"
             StartupUri="MainWindow.xaml">
    <Application.Resources>
        <SolidColorBrush x:Key="DefaultWhite">#FFFFFF</SolidColorBrush>
        <SolidColorBrush x:Key="DefaultGray">#D3D3D3</SolidColorBrush>
        <SolidColorBrush x:Key="DefaultPurple">#A163F5</SolidColorBrush>

        <Style TargetType="Button" x:Key="DefaultButton">
            <Setter Property="Height" Value="30"></Setter>
            <Setter Property="Width" Value="Auto"></Setter>
            <Setter Property="Background" Value="{StaticResource DefaultPurple}"></Setter>
            <Setter Property="Foreground" Value="{StaticResource DefaultGray}"></Setter>
        </Style>

        <Style TargetType="TextBlock" x:Key="RightSideTextBlock">
            <Setter Property="HorizontalAlignment" Value="Right"></Setter>
            <Setter Property="VerticalAlignment" Value="Center"></Setter>
        </Style>
        <Style TargetType="TextBox" x:Key="VerticalTextBox">
            <Setter Property="VerticalAlignment" Value="Center"></Setter>
        </Style>
    </Application.Resources>
</Application>