EmployeeTracker/InvestTracker/Styles/MainStyle.xaml

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <Style TargetType="{x:Type Label}">
        <Setter Property="Background" Value="Transparent"/>
        <Setter Property="Padding" Value="0"/>
    </Style>

    <Style TargetType="{x:Type Frame}">
        <Setter Property="Background" Value="#ddd"/>
        <Setter Property="Margin" Value="8"/>
    </Style>

    <Style x:Key="NavButton" TargetType="{x:Type Button}">
        <Setter Property="Margin" Value="0,8"/>
    </Style>

    <Style x:Key="ValidationFail" TargetType="{x:Type TextBox}">
        <Style.Triggers>
            <Trigger Property="Validation.HasError" Value="True">
                <Setter Property="Background" Value="Red"/>
                <Setter Property="BorderThickness" Value="1" />
                <Setter 
                    Property="ToolTip"
                    Value="{Binding RelativeSource={RelativeSource Self},
                    Path=(Validation.Errors)[0].ErrorContent}"/>
            </Trigger>
        </Style.Triggers>
    </Style>
</ResourceDictionary>