New Post: PropertyGrid custom type error

I have a TargetPropertyType registered as DependencyProperty but work only with incorrect type

<xctk:EditorTemplateDefinition  >
    <xctk:EditorTemplateDefinition.TargetProperties >
        <xctk:TargetPropertyType Type="{x:Type myType}" />
    </xctk:EditorTemplateDefinition.TargetProperties>  
<xctk:EditorTemplateDefinition.EditingTemplate>
    <DataTemplate>
        <Grid VerticalAlignment="Center" HorizontalAlignment="Stretch">
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="*" />
                <ColumnDefinition Width="Auto" />
            </Grid.ColumnDefinitions>
            <TextBlock  Background="{Binding Value.Brush}"/>
            <Button Grid.Column="1" Content=". . ."/>
        </Grid>
    </DataTemplate>
</xctk:EditorTemplateDefinition.EditingTemplate>

Work but incorrect
Public Shared ReadOnly BrushProperty As DependencyProperty = DependencyProperty.Register("Brush", GetType(Brush), GetType(Brush))


Dont'Word but correct
Public Shared ReadOnly BrushProperty As DependencyProperty = DependencyProperty.Register("Brush", GetType(Brush), GetType(myType))

How can I use the correct method?