Bob, your stones are all different colours. Here's a quick render with all your PF's used for colouring the stones replaced with a simple basic test colour, they're all there as different colours. But note that they are all varying in shades and degree of "purity".
Something else in your setup is having a direct influence on their colours and making them all very similar (your original colours were all closer than the ones I chose, see modified tgd). I also shifted a few things around to a format I'm more used to working with.
Hope this helps.