ok,hopefully these will help a bit.
When I first saw the bowl, I think (but it's a long time ago), that it was displayed under fluorescent/longlife light bulb) so it showed as amethyst.
When I got it home under my tungsten lighting it displays as grey as per previous photos.
However, I've just now taken some pictures under LED lighting and they have actually shown it as amethyst which is the colour it looks under LED as well.
So this is as far as I can get, a pretty good representation of the amethyst colour it looks under long life and fluorescent lighting (pics now attached).
It doesn't have two colours in it although one shot I've attached in the second set of photos below shows one of the pulls as navy blue. The last shows it again taken tonight, under tungsten lighting and it's grey.
I hope these help

m