I'd start with clear and use plain pearl powder, then add a very small bit of white with an even smaller amount of yellow to tone it to get the base color then add violet hi lite for the purple sheen. I haven't seen anyone's actual recipe for a ghost color, as they are referred, to like this. Do small, controllable batches until you get the base color then add the hi lite. There seems to be a small yellowish tint to the pearl, hence the very small amount of yellow to the plastic.