Access Material Theme Properties in a .ui.qml file

[SwyssX]

Hello,

I have a QtQuick UI Form that has a designer editable .ui.qml using the Material Theme

Page {
    width: 1700
    height: 750
    property alias busyIndicator1: busyIndicator1
        BusyIndicator {
            id: busyIndicator1
            x: 391
            y: 391
        }

}

And i the .qml file I want to change the The Material Accent

import QtQuick 2.4
import QtQuick.Controls 2.4
import QtQuick.Controls.Material 2.4

AutomaticModeForm {

  busyIndicator1{
      Material.accent: Material.Red
  }
}

If I start I get the QML Error qrc:/AutomaticMode.qml:19 Attached properties cannot be used here

Which is clear as I have to make the Material property accessible.

I also tried per Hand to add property alias Material: accent to the qml.ui
but this does not seem to work.

Page {
    width: 1700
    height: 750
    property alias busyIndicator1: busyIndicator1
    property alias Material: accent
        BusyIndicator {
            id: busyIndicator1
            x: 391
            y: 391
        }

}

What is the correct way to make the Material property accessible?

Kindest Regards & Big thanks

Erik