It is really strange that it turns green just over one night. I am not sure what kind of water you used as substitute of contact lenses care solution. Normally speaking, if you happen to be a dilemma that you need to take off the contact lenses and you are out of care solution, you can use saline water, distilled water or moisturizing eye drops to wash and store the lenses. Because after wearing, the lenses are full of secretion, protein or even bacteria, if you just put them into water, it might be contaminated with germs so that it becomes green. You can't use it any more otherwise your eyes would probably be infected. Go to the nearest shop to get a new pair.
It seems that some sort of chemical in the water that your contact lenses react with the chemical in the water. If so, you shall give up the contact lenses and buy other new contact lenses for the sake of your eye health. And just remember that you shall keep your contact lenses in special contact lenses solution. And not put it in water since the tap water contains many invisible bacterium.
I can see that there is something wrong with your lenses. And definitely. they cannot be used any more, because those contact lenses could be highly dangerous, which could transmit some bacterium to your eyes. The different color represents some problems with them, so you should abandon those lenses without hesitation. Of course that is abnormal, just get another pair, or just give it up.