When I read more of the cuttings I have on the Andamooka Opal, I saw that this one says that the opal is white



and this which also says that the opal is white.



In my opinion a "white" opal fits better with what can be seen in contemporary photographs, particularly when the opal was photographed on the Queen.



Reports state that HM's dress was blue -- I suspect a pale blue -- and her fur jacket was white, so it is unlikely that the opal would show as so light a colour in photos if the base colour was a deeper blue as the photo on the Altamann site would suggest.

I suspect that this photo, while not capturing the flashes of fire and colour which would be seen as the opal caught the light, is nearer to reality.