Как поменять цвет рамки оконного приложения WPF?

https://ru.stackoverflow.com/questions/859295/Как-сделать-цвет-окон-wpf-приложения-таким-же-как-цвет-windows10 попытался сделать так, как объясняют здесь, но ловлю ошибку, что контент можно объявить только один раз

вот текущий код:

<Window x:Class="DocX_WordMaker_WPF.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:local="clr-namespace:DocX_WordMaker_WPF"
    mc:Ignorable="d"
   
    Title="MainWindow" Height="450" Width="800">

<Window.Resources>

    <Style x:Key="FocusVisual">
        <Setter Property="Control.Template">
            <Setter.Value>
                <ControlTemplate>
                    <Rectangle Margin="2" StrokeDashArray="1 2" Stroke="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}" SnapsToDevicePixels="true" StrokeThickness="1"/>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
    <SolidColorBrush x:Key="Button.Static.Background" Color="#FFDDDDDD"/>
    <SolidColorBrush x:Key="Button.Static.Border" Color="#FF707070"/>
    <SolidColorBrush x:Key="Button.MouseOver.Background" Color="#FFBEE6FD"/>
    <SolidColorBrush x:Key="Button.MouseOver.Border" Color="#FF3C7FB1"/>
    <SolidColorBrush x:Key="Button.Pressed.Background" Color="#FFC4E5F6"/>
    <SolidColorBrush x:Key="Button.Pressed.Border" Color="#FF2C628B"/>
    <SolidColorBrush x:Key="Button.Disabled.Background" Color="#FFF4F4F4"/>
    <SolidColorBrush x:Key="Button.Disabled.Border" Color="#FFADB2B5"/>
    <SolidColorBrush x:Key="Button.Disabled.Foreground" Color="#FF838383"/>
    <Style x:Key="MidnightGreenButtonStyleRounded" TargetType="{x:Type Button}">
        <Setter Property="FocusVisualStyle" Value="{StaticResource FocusVisual}"/>
        <Setter Property="Background" Value="{StaticResource Button.Static.Background}"/>
        <Setter Property="BorderBrush" Value="{StaticResource Button.Static.Border}"/>
        <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}"/>
        <Setter Property="BorderThickness" Value="0"/>
        <Setter Property="HorizontalContentAlignment" Value="Center"/>
        <Setter Property="VerticalContentAlignment" Value="Center"/>
        <Setter Property="Padding" Value="1"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type Button}">
                    <Border x:Name="border" CornerRadius="20" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" SnapsToDevicePixels="true">
                        <ContentPresenter x:Name="contentPresenter" Focusable="False" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" Margin="{TemplateBinding Padding}" RecognizesAccessKey="True" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}"/>
                    </Border>
                    <ControlTemplate.Triggers>
                        <Trigger Property="IsDefaulted" Value="true">
                            <Setter Property="BorderBrush" TargetName="border" Value="{DynamicResource {x:Static SystemColors.HighlightBrushKey}}"/>
                        </Trigger>
                        <Trigger Property="IsMouseOver" Value="true">
                            <Setter Property="Background" TargetName="border" Value="MediumSpringGreen"/>
                            <Setter Property="BorderBrush" TargetName="border" Value="MediumSpringGreen"/>
                        </Trigger>
                        <Trigger Property="IsPressed" Value="true">
                            <Setter Property="Background" TargetName="border" Value="#00c87B"/>
                            <Setter Property="BorderBrush" TargetName="border" Value="#00c87B"/>
                        </Trigger>
                        <Trigger Property="IsEnabled" Value="false">
                            <Setter Property="Background" TargetName="border" Value="{StaticResource Button.Disabled.Background}"/>
                            <Setter Property="BorderBrush" TargetName="border" Value="{StaticResource Button.Disabled.Border}"/>
                            <Setter Property="TextElement.Foreground" TargetName="contentPresenter" Value="{StaticResource Button.Disabled.Foreground}"/>
                        </Trigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
</Window.Resources>
<Grid Background="#FF00C87B" >

    <Button x:Name="Button1" Style="{DynamicResource MidnightGreenButtonStyleRounded}" Content="Button1" HorizontalAlignment="Left" Margin="10,295,0,0" VerticalAlignment="Top" Click="Button_Click" Background="MediumSpringGreen" Height="74" Width="130"/>
    <Button x:Name="button2" Content="Button2" HorizontalAlignment="Left" Margin="152,295,0,0" VerticalAlignment="Top" Height="83" Width="159" Click="button2_Click" Style="{DynamicResource MidnightGreenButtonStyleRounded}" Background="MediumSpringGreen"/>
    <Button Content="Button" HorizontalAlignment="Left" Margin="349,295,0,0" VerticalAlignment="Top" Height="83" Width="127" Style="{DynamicResource MidnightGreenButtonStyleRounded}" Background="MediumSpringGreen"/>

</Grid>

как вставить этот кусок кода в мой проект?

<Window.Background>
    <SolidColorBrush Color="{DynamicResource {x:Static SystemColors.WindowColorKey}}"/>
</Window.Background>

в конечном итоге нужно поменять цвет этой белой рамки, но из-за того, что у меня не получается вставить код выше в свой проект я не знаю как....