I have a very specific question. I could not find any answers for this exact problem, so I used the trial and error method to pinpoint the problem. Here is an example code I hav
The CommandBar on Windows Phone is system UI and cannot be customized by the app beyond setting it's foreground and background colors.
If you want to customize the individual buttons you'll need to implement your own panel for them instead of using the app bar. You can place a horizontal Stack Panel at the bottom of your page and include customized AppBarButtons in it. If you want it to shoe and hide you will need to set your own logic to detect the triggering input and then apply an animation to side it open and closed.