when using dark theme of Material style, I can't see the text of TreeViewDelegate.

on Archlinux, system wil setstyle automatically, may include some pallet setting using system theme setting, but the setting in env/conf will not work.

after that, call setstyle to set Material style, we will get the effect in the picuture.

I checked the source code of Material TreeView/Delegate, it is using pallet against Material.xxx, but no pallet in other Material/xxx.qml files.