There is no sunlight here today but here is my Blue 15 Pro in the Amethyst Sheath.My dispatched email for the blue also featured the amethyst design, so I think it's just a stock photo for the sheath.
It did make me think what the blue PM would look like in an amethyst case though, to the extent that when I come to order the new version of the sheath, I think I'm going to order amethyst. The blue case is fantastic, but the amethyst is a gorgeous colour and the little hint of blue around the lenses would look really nice.