Had a look through my resources but sadly I must have remembered wrongly as I can't find this model. While as Frank says the coloured stain/ patina was mostly a French technique, Inwald at least used similar applied colours. Several Barolac pieces are known with this effect -- for example the 'Loss of the Revenge' vase shown in Manley has a green stain, while I've had floral vases of theirs with various coloured stains.