Hmmm, mine we're never yellow, just kind of cloudy and bloodshot. I used to swear my contacts were bugging me( never dawned on me it was all the stinkin' vodka). After 35 days, they're back to normal. You could even say they have that "sparkle" again.
Sorry that didn't answer your question. I even tried to google it for you. Thought maybe there would be some situation similar to yours somewhere out there. Didn't come up with squat.
So anyway, sorry for the massive non-answer.