The idea of eye color changing under the force of strong emotion is by no means unique to the Mary-Sues - nor to the realm of fantasy, either. Just see Agatha Christie - classic detective fiction! - and her most famous detective, Hercule Poirot. When he has an illumination (as opposed to a 'little idea'
) she writes that his eyes shine green. I'd post an example, but I have none of my books with me at present. I can't remember, however, if she specifies his ordinary eye color.
Nuranar,
whose eyes are a most disappointingly-uniform deep blue (but not 'Lijah blue, thank you! deeper than that
)