It's a two pin MR16 bulb that has three colors: green, yellow, and pink. Depending on the angle with which the bulb hits the fountain, the color is one of those three I listed. If you look at the bulb from one angle it looks pink and from another angle it looks green and when the two combine it looks yellow. A lot of the MR16 bulbs have a clear piece of glass covering the bulb, this is like a reflective piece of glass like a mirror. If you stare directly at the bulb straight on, you can see yourself.