Slight crisis.

palette was introduced in QtQuick.Controls 2.3 (Qt 5.10)
Frameworks is supposed to support 5.9

(confusingly we have a report on IRC from someone who does have 2.3 https://paste.opensuse.org/8636292 but it still gives an error)

The property is marked as FINAL in the template, so we can't redeclare it. I think our only option will be some sort of

Component.onCompleted: {if we have the property, bind it}