I may tweak these further later, but for now I am quite satisfied.
The "grey" color is how they look when "white". The effect works better with lighter colors, otherwise it just looks like they have a single-color iris (which can look cool sometimes). They also look nice when all black, like in the fourth picture.
The little bright spot on the left side is part of the texture, not lighting. The brighter round spot is something in-game lighting makes appear on eyes. For some reason, girl eyes are flipped- if something is on the left, it seems to be on the right on a girl's right eye (see the 5th pic for an example).