uwp acrylic tint color black appears dark gray

Question

In my uwp app I am trying to use the Acrylic Brush, I made a custom one because the default ones are not working for me. But if you notice here I have attached image from Microsoft docs and on right side is window of my app showing acrylic completely different on same background.

Code

 <AcrylicBrush
                            x:Key="AppBackgroundAcrylicBrush"
                            BackgroundSource="HostBackdrop"
                            FallbackColor="Black"
                            TintColor="Black"
                            TintLuminosityOpacity="0.1"
                            TintOpacity="1" />

After that I tried luminosity to be 0.9 and now it looks dark grayish. But I want it to look jet black color Acrylic with small transparency. Basically I want it to look like as the image shows on left side as in Microsoft docs with 10% luminosity and 100% tint opacity.

Code

   <AcrylicBrush
                            x:Key="AppBackgroundAcrylicBrush"
                            BackgroundSource="HostBackdrop"
                            FallbackColor="Black"
                            TintColor="Black"
                            TintLuminosityOpacity="0.9"
                            TintOpacity="1" />

Docs: https://learn.microsoft.com/en-us/windows/uwp/design/style/acrylic

Answer 1

Basically I want it to look like as the image showson left side as in microsoft docs with 10% luminosity and 100 % tint opacity.

Update

Base on the testing, TintLuminosityOpacity 0.9 and TintOpacity 1.0 could render you mentioned jet black color AcrylicBrush. But that is not conformity with document. And the AcrylicBrush looks dark gray. It is strange, I will report to related team. Currently, please try use the following to replace.

<AcrylicBrush
    x:Key="CustomAcrylicBrush"
    BackgroundSource="Backdrop"
    FallbackColor="Black"
    TintColor="Black"
    TintLuminosityOpacity="1.0"
    TintOpacity="1"
    />