Three of my girls have blue eyes, one has brown. I figure the blue comes from the Cambodian gene, as my red male has them too (and he started out his life with Cambodian red coloring). One of the blue eyed females is a greyish/red color, one is a stripey black with some blue and red spotching on her fins, and the last is a red Cambodian.
The one girl and my black male have brownish eyes, but you can still distinguish the iris and the pupil. I have seen the all black eyes as well; hmmm. I wonder if that is just another variation.
I figure they are all lovable, regardless of eye color. But I admit that I'd be a little wierded out with the "empty eye" look, prolly for just a minute though. You all have beautiful fish!