In The Quest For The Dragons Egg (a.k.a. the gamebook section of The Forbidden Gate, the fifth Knightmare book), Motley recites a rhyme about islanders with 'xanthous gaze' or 'eyes of virid hue' who the player may encounter later on. You have written in the Interactive Knightmare Lexicon about other aspects of this gamebook, so perhaps you had 'virid hue' in your head without realising.
Oh yeaahhh, I remember that now you mention it. The word choice in the fanfic really was coincidental (I considered a whole bunch of synonyms before settling on "virid"), but that's probably why it sounded so right to me!