WPF ListBoxItem: Overwrite SystemColors by Style has no effect

Question

I'd like to overwrite SystemColors of a ListBoxItem . My target is to change the background of a selected but not focused item. By default it is grayed out when focus is lost eg. by showing the context menu. I do not want fancy complex style-sugar-code, just something very simple. I found several threads on the net about overwrite the SystemColors but non of them worked.

The following copy-paste-code does not work and the brushes will be ignored and it has no effect.

<Window x:Class="WpfAppListBoxItemBrushes.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:sys="clr-namespace:System;assembly=mscorlib"
    mc:Ignorable="d"
    Title="MainWindow" Height="200" Width="400">
<ListBox>
    <ListBox.ItemsSource>
        <x:Array Type="sys:String">
            <sys:String>1st item</sys:String>
            <sys:String>2nd item</sys:String>
        </x:Array>
    </ListBox.ItemsSource>
    
    <ListBox.ContextMenu>
        <ContextMenu>
            <MenuItem Header="Test"/>
        </ContextMenu>
    </ListBox.ContextMenu>

    <ListBox.Resources>
        <Style TargetType="ListBoxItem">
            <Style.Resources>
                <SolidColorBrush x:Key="{x:Static SystemColors.ActiveBorderBrushKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.ActiveBorderColorKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.ActiveCaptionBrushKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.ActiveCaptionColorKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.ActiveCaptionTextBrushKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.ActiveCaptionTextColorKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.ControlBrushKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.ControlColorKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.ControlDarkBrushKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.ControlDarkColorKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.ControlDarkDarkBrushKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.ControlDarkDarkColorKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.ControlLightBrushKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.ControlLightColorKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.ControlLightLightBrushKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.ControlLightLightColorKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.ControlTextBrushKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.ControlTextColorKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.InactiveBorderBrushKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.InactiveBorderColorKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.InactiveCaptionBrushKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.InactiveCaptionColorKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.InactiveCaptionTextBrushKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.InactiveCaptionTextColorKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.InactiveSelectionHighlightBrushKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.InactiveSelectionHighlightTextBrushKey}" Color="Red" />
            </Style.Resources>
        </Style>
    </ListBox.Resources>
</ListBox>

The style definition has no effect on the ListBoxItem at all. What's wrong with this code?

Answer 1

Try to move colors to Resources of ListBox . It should alters system colors only for this ListBox and its children ( ListboxItems ).

<ListBox.Resources>
        <SolidColorBrush x:Key="{x:Static SystemColors.ActiveBorderBrushKey}" Color="Red" />
        <SolidColorBrush x:Key="{x:Static SystemColors.ActiveBorderColorKey}" Color="Red" />
        <SolidColorBrush x:Key="{x:Static SystemColors.ActiveCaptionBrushKey}" Color="Red" />
        <SolidColorBrush x:Key="{x:Static SystemColors.ActiveCaptionColorKey}" Color="Red" />
        <SolidColorBrush x:Key="{x:Static SystemColors.ActiveCaptionTextBrushKey}" Color="Red" />
        <SolidColorBrush x:Key="{x:Static SystemColors.ActiveCaptionTextColorKey}" Color="Red" />
        <SolidColorBrush x:Key="{x:Static SystemColors.ControlBrushKey}" Color="Red" />
        <SolidColorBrush x:Key="{x:Static SystemColors.ControlColorKey}" Color="Red" />
        <SolidColorBrush x:Key="{x:Static SystemColors.ControlDarkBrushKey}" Color="Red" />
        <SolidColorBrush x:Key="{x:Static SystemColors.ControlDarkColorKey}" Color="Red" />
        <SolidColorBrush x:Key="{x:Static SystemColors.ControlDarkDarkBrushKey}" Color="Red" />
        <SolidColorBrush x:Key="{x:Static SystemColors.ControlDarkDarkColorKey}" Color="Red" />
        <SolidColorBrush x:Key="{x:Static SystemColors.ControlLightBrushKey}" Color="Red" />
        <SolidColorBrush x:Key="{x:Static SystemColors.ControlLightColorKey}" Color="Red" />
        <SolidColorBrush x:Key="{x:Static SystemColors.ControlLightLightBrushKey}" Color="Red" />
        <SolidColorBrush x:Key="{x:Static SystemColors.ControlLightLightColorKey}" Color="Red" />
        <SolidColorBrush x:Key="{x:Static SystemColors.ControlTextBrushKey}" Color="Red" />
        <SolidColorBrush x:Key="{x:Static SystemColors.ControlTextColorKey}" Color="Red" />
        <SolidColorBrush x:Key="{x:Static SystemColors.InactiveBorderBrushKey}" Color="Red" />
        <SolidColorBrush x:Key="{x:Static SystemColors.InactiveBorderColorKey}" Color="Red" />
        <SolidColorBrush x:Key="{x:Static SystemColors.InactiveCaptionBrushKey}" Color="Red" />
        <SolidColorBrush x:Key="{x:Static SystemColors.InactiveCaptionColorKey}" Color="Red" />
        <SolidColorBrush x:Key="{x:Static SystemColors.InactiveCaptionTextBrushKey}" Color="Red" />
        <SolidColorBrush x:Key="{x:Static SystemColors.InactiveCaptionTextColorKey}" Color="Red" />
        <SolidColorBrush x:Key="{x:Static SystemColors.InactiveSelectionHighlightBrushKey}" Color="Red" />
        <SolidColorBrush x:Key="{x:Static SystemColors.InactiveSelectionHighlightTextBrushKey}" Color="Red" />
    </ListBox.Resources>

Answer 2

I am afraid this is not possible because the brushes are hardcoded in the default template of the ListBoxItem .

So you will have to copy the entire template into your XAML markup and then modify it as per your requirements.

You cannot "override" the brushes without using a custom template.