Crash when creating an alias from a variable

import QtQuick 2.12
import QtQuick.Studio.Components 1.0
import QtQuick.Controls 2.3
import QtQuick.Layouts 1.0
import QtQuick.Dialogs 1.3


Item {
    id: myItem

    property alias myColorDialogName: myItem.myColorDialogName
    property var colourDialogName: colorDialog1




    ColorDialog {
        id: colorDialog
        title: "Please choose a color"

        onAccepted: {
            console.log("You chose: " + colorDialog.color)
            chosenColour.color = colorDialog.color
        }

        onRejected: {
            console.log("Canceled")
        }

        Component.onCompleted: {
            visible = true
        }
    }
}