Yes i tried balck outline on the eyes, but the result is bad !
I'll test some darker blue. , yes the eyes don't popup enought and that what's sould popup a little in characters !

For the resolution i'm stuck with 128*128, i have done the UV with some quick unwrap, no real work on UV to optimise them !
So it's somewhat to late now.
But i'll do it for next models indeed laugh