Context menus in build 10547 are easier to customize now.
No more need for additional fillcolors, borders etc
Black is Fonts & System Metrics > BTNSHADOW
Yellow is Unknown > ImmersiveStart::Menu > PopUpBackground > FILLCOLOR
Green is Unknown > ImmersiveStart::Menu > PopUpItem > Normal
Pink is Unknown > ImmersiveStart::Menu > PopUpItem > Hot
White is Unknown > ImmersiveStart::Menu > PopUpSeparator
Same goes for the new taskbar context menus or Unknown > ImmersiveStartDark::Menu