Shapes lose some style information

[TwoWheelDev]

For the the following simple topology I have placed two shapes, one ellipse and one rectangle.

The ellipse has been changed to be 100% transparent (alpha level 0) and the rectangle yellow with no border also dropped to the background layer.

{
    "name": "unsaved",
    "resources_type": "local",
    "topology": {
        "ellipses": [
            {
                "border_style": 2,
                "color": "#ffffff",
                "height": 200.0,
                "transparency": 0,
                "width": 200.0,
                "x": -222.0,
                "y": -109.0
            }
        ],
        "rectangles": [
            {
                "border_style": 0,
                "color": "#ffff00",
                "height": 100.0,
                "width": 200.0,
                "x": -75.0,
                "y": -50.0,
                "z": -1.0
            }
        ]
    },
    "type": "topology",
    "version": "1.2.1"
}

This is all saved correctly as can be seen in the topology file above, but when the file is opened again it loses some information.

In particular the transparency is lost on the ellipse and the recatangle regains its border.