Welcome to the wonderful phase in your tattoo called: Silver-Skin.
When your tattoo is peeling, your skin underneath attempts in one last line of defense to protect itself with this shiny layer of skin. Do not fret, however. The silver/grey tone you are seeing is just these final stages of your tattoo healing.
Essentially, your skin will peel, the silver will show through and make the tattoo appear VERY faded. What you can do to help get rid of this strange layer of skin, is to go to your local Walmart or Target, and get a bottle of Vitamin E gel capsules. Break open a capsule and rub it gently all over your tattoo. I would do this about twice daily.
Give it about a week, and your tattoo will be much more vibrant. Once this grey " mask" is gone, I guarantee that you will be satisfied!
Good luck, dear :]
EDIT: Just for the record, the poster who says that his artist told him to wear saran wrap on his tattoo was very, very misinformed. Wearing any sort of bandage over your tattoo can cause moisture build up, and can actually pull out the color.