How to change AppBar styles in Windows 8.1 Universal apps

[+Biscuits Brown MVC]

I'm working on my first universal app. Its astronomy related and I thought a nice feature would be to offer the option for a 'night mode' where the entire screen goes from white foreground/black background to red foreground/black background. The only thing I can't get to change is the actual AppBar buttons - and its not the whole button. I can get actual glyph to change to red, its the button outline that stays white. I suspect there is a style I can apply but I can't figure this out. This is my first attempt at XAML and I'm just not seeing how to do this.

 

I've Googled (and Bing'd just to get alternate results) it find all kinds of references to doing it in regular 8.0 store apps but the AppBar in 8.1 removed some of the (obvious) styling. I can cheat and just provide red versions of the icons themselves and I'm about ready to go that route but thought I'd give it one more try and ask here.  

 

Anyone have any experience applying a style to the AppBar in an 8.1 universal app?

[SledgeNZ]

AppBar is looking as though it will be outdated in Win10.

 

I'd go for ease of use and have it as an option onscreen that toggles between the two modes. Just setup two buttons with different styles and have Visibility set based on which mode you're in.

[+Biscuits Brown MVC]

Thanks SledgeNZ, I was actually thinking along that same line but it just felt wrong - but then again you are right about Win10 so your suggestion is likely the best course of action at this time. Thanks!