I think lighter colored eyes are more prevalent in Aquarius and Gemini, particularly a very clear light blue.
Libra veers towards hazel, or having gold flecks.
Earth eye color tends to be on the darker/muddier side.
Scorpios are majority dark eyes, like their hair, but seem to have a significant minority group in the reverse (much like in the case of Cancer body types), with blond hair and icy blue eyes.
Cancer and Pisces eyes I'd say are less often brown than blues, greens, and greys, often a bit murky in their coloring, but are most notable and consistent for their shape and... for lack of a better word, texture.
I haven't noticed any particular patterns in the eye colors of fire signs, but that could easily be my own fault.