Created Unassigned: DateTimeUpDown : spinner background color is gray on Windows 8 [21729]

Hi,

I'm using the NuGet package Extended WPF Toolkit (2.3)

Here is my DateTimeUpDown under Windows 7 :


And the same under Windows 8 :


My first attempt was to include the PresentationFramework.Aero.dll as an embedded resource and add it to the ResourceDictionary in my App.xaml

```
<ResourceDictionary Source="/PresentationFramework.Aero;component/themes/Aero.NormalColor.xaml"/>
```

but the spinner still have this gray background.

Any idea ?

Thanks !