You can put 2 drops of rosewater everyday, which will clean your eyes & the yellow color will gradually be removed.

I think she means the yellow from the whites, not the iris itself. Just any normal allergy eyedrops are a good quick fix, otherwise you can try more complicated eye-whitening tactics.

Eye colour is predetermined by your genetic make up, although enivironmental factors can subtly affect the natural pigmentation of the iris. It is not possible to change your eye colour naturally, however you may be able to artifically change eye colour using contacts.