The Lava Lamp is a static lamp. It can be purchased for 1,800 Bells, and sold for 450 Bells at Re-Tail (360 Bells at Nooklings).
Customizing the Lava Lamp costs 180 Bells. To return it to its original state, it costs half the price (90 Bells).
There 6 options for customizing the lamp color. There are no ore customizations for this item.
There is a glitch in the North American version of the game where the options do not match up with the outcome. The customization list below reflects the North American version. Other versions of the game will come out accurately.