My belly button is darker around the piercing but its not infected is there any common stuff i can do to get it back to the normal color of my skin?

Time may be your only solution. The darkness comes from the skins reaction to the piercing. It noted something that didn't belong there was there. The response of skin is to increase melanin production, the thing that causes skin color. Once skin cells in the area realize that piercing is nothing to worry about, they will decrease their melanin production and things will slowly return to normal.

I would take out the ring or get one pure silver or gold.