Set the MenuItem BackGround color (The right way)

Whenever I try to change the background color to a menu adding the following code to the app.xml

    <Style TargetType="MenuItem">
        <Setter Property="Background" Value="#FF9B9B开发者_开发知识库9B" />
    </Style>

I get this lighter shade of gray around the menu, which color isn't set by the background property:

I know there are similar questions around, but the answers I've found haven't helped me.

That sort of thing is coded into the various ControlTemplates for MenuItems. You will probably have to create your own. (You could copy the defaults and edit them to your liking though)