Purple, they mean. But then why, please, does it and it's water turn prussian blue (according to painter daughter) Â in cooking. Shades of woad! = Tim
(http://www.hpphoto.com/servlet/LinkPhoto?GUID=31914b2c-7ed5-2ae7-7001-30c115923306&size=lg)
Just checked the watercolours, - definitely Prussian Blue