title: How do I create a custom QML Control that respects the Material Style colors?
body: <p>I am creating a custom Control in QML for my application.  I want to run on both desktop and Android, so I'm using Material Style for the application.  This applies a colour scheme to all existing Qt Quick Controls 2 controls (buttons, toolbars, etc).  But how do I use those colours on my control?  I know I can just use the same colours with a hex code or whatever, but I want my control's colours to change if I change the accent colour in the theme, etc.</p>
  
  <p>I've tried <code>SystemPalette</code> but the colours there don't seem to follow Material Style but rather always follow the default style.</p>
  
  <p>Is it possible for me to get access to the Material colours?  What will happen if the application is run in non-Material mode?</p>