Does anyone know a simple XAML solution to change the entire background of a ToolTip?

I did the following:

<Image Height="16" Source="Images/Icons/Add2.png" Stretch="Fill" Width="16" Opacity="0.99" Grid.Column="0">
    <Image.ToolTip>
        <Grid Background="#000000">
             <Grid.RowDefinitions>
                <RowDefinition />
                <RowDefinition />
             </Grid.RowDefinitions>
             <TextBlock Text="Header1" FontSize="15" Grid.Row="0"/>
             <TextBlock Text="Subitem" FontSize="12" Grid.Row="1"/>
         </Grid>
    </Image.ToolTip>
</Image>

But the result looks like that:

Tooltip background color

Any suggestions?

c# wpf xaml background tooltip
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