aistudio-wpf-diagram/AIStudio.Wpf.DiagramDesigner/Themes/ConnectorItem.xaml

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                    xmlns:s="clr-namespace:AIStudio.Wpf.DiagramDesigner"
                    xmlns:c="clr-namespace:AIStudio.Wpf.DiagramDesigner.Controls">

    <DataTemplate DataType="{x:Type s:FullyCreatedConnectorInfo}">
        <Grid Width="{Binding ConnectorWidth}" Height="{Binding ConnectorHeight}">
            <Grid.ContextMenu>
                <ContextMenu ItemsSource="{Binding MenuOptions}" >
                    <ContextMenu.ItemContainerStyle>
                        <Style TargetType="MenuItem">
                            <Setter Property="MenuItem.Header" Value="{Binding Text}" />
                            <Setter Property="MenuItem.ItemsSource" Value="{Binding Children}" />
                            <Setter Property="MenuItem.Command" Value="{Binding Command}" />
                            <Setter Property="MenuItem.Icon" Value="{Binding Icon}" />
                            <Setter Property="CommandParameter" Value="{Binding CommandParameter}" />
                            <Setter Property="MenuItem.IsCheckable" Value="{Binding IsCheckable}" />
                            <Setter Property="MenuItem.IsChecked" Value="{Binding IsChecked}" />
                        </Style>
                    </ContextMenu.ItemContainerStyle>
                </ContextMenu>
            </Grid.ContextMenu>
            <!-- transparent extra space makes connector easier to hit -->
            <Rectangle Fill="Transparent" Margin="-2" />
            <Rectangle Fill="{Binding ColorViewModel.FillColor,Converter={StaticResource ColorBrushConverter}}"  StrokeThickness="1" Stroke="{Binding ColorViewModel.LineColor,Converter={StaticResource ColorBrushConverter}}" />
        </Grid>
    </DataTemplate>

    <!-- DragThumb Default Template -->
    <Style TargetType="{x:Type c:DragThumb}">
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type c:DragThumb}">
                    <Rectangle Fill="Transparent" />
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>


</ResourceDictionary>