... hmmm.... then may I suggest a magenta Iris with glow effects? The "white" of the eye should be white... or close to it... or it just looks weird. And the "white" should be different than the iris color.
i know it isnt supposed to look realistic, but it should look within the realm of possibility... i like the green again in the bigger pics because its more subtle, catches the eye less conspicuously.
The red almost looks like he got a bad burn on his face when young... if seen burn victims with eyes like that (that wasnt criticism, i was being serious)
the blue looks kinda pasted on... maybe you just need two shades of blue, one for the iris and one for the "white"