How to clean a tarnished ring?

Okay, I bought this ring. It is metal (i think) and it was originally gold (it had some spots on it, I don't know what of). So, I had this ring for 2 days and it is already tarnished! (It is fake gold, but still!) It is now silver with blotches of pink on it. ! How do I clean it so it can appear just one natural color (silver, gold, or pink [lol] )