Setting default color of the diagram to null

I have been creating diagrams that require the color to be null. I defined the fill to be null in the node dataarray .I am having an inspector with many properties like fill,stroke, strokewidth,size etc. When I am trying to change the stroke color in the inspector, the diagram automatically takes a fill color that is set as default. Is there any way to retain the fill to be null throughout.?

The DataInspector uses the HTML Input element’s support for the type “color”, meaning RGB. But that means there is no support for transparency, RGBA.

So if you really want this, you’ll either need to replace the color picker that is used by the DataInspector, or you’ll need to add a separate data property that you use to generate an RGBA value.