Understand, this is not some gimmicky lamp that will try to predict your mood. No no no. This is a magical lamp that causes people's moods to... shift in certain ways. A full spectrum of colors, a full spectrum of possibilities. Let the mood strike you with the Spectrum Mood Lamp.
The Spectrum Mood Lamp is a special lamp which is introduced in The Sims 3: Supernatural. It can be found on Parties under Entertainment or Table Lamps under Lighting, both categories in Buy mode.
Not only the lamp lights up in six different colors, it can change the moods of nearby Sims. Each different color gives out each moodlet and out of the six moodlets, one of them is negative, which is the "Feeling Blue" moodlet.
The lamp can also attract zombies. This can distract them from eating plants in a lot. A fairy can shrink into their natural form and play around inside the lamp, but there is a chance they may get electrocuted, get singed, or death by electrocution.
There have been reports that the moodlets caused by the lamp tend to get stuck when Sims leave the room with the lamp, or even after the lamp has been sold. The simple workaround is to buy the lamp and turn it off manually or removing the moodlet by using testingcheatsenabled true, pressing the CTRL button and clicking it.