The mystery of how a lava lamp works comes down to the properties of its ingredients. When the waxy mass inside the lamp heats up, it becomes less dense than the surrounding liquid and rises. It falls when it cools at the top of the lamp. The original and newer versions come in several colors, so you can pick one to go with your room.
A black light emits ultraviolet light and interacts with certain materials to create florescence. Neon colors create this effect, which is why "black-light" posters featuring neon colors, sometimes with black velvet, became popular to hang in a room with a black light.
Decorating the room with black-light tubing can take a room with a lava lamp from retro to Space Age. Rather than displaying one lava lamp, grouping lava lamps in front of a mirror intensifies the effect, making the hypnotic lava lamp motion visible from multiple angles around the room. Hanging mirrors or positioning mirrored furniture such as dressers all the way around the room creates an infinity effect in the reflections. A lava lamp used as night-light, white mobiles to glow in the black light, white curtains, and textured white or neon throws, such as faux fur or chenille, create a bright glow to make the most of the black light.
Your choice of colors and accessories plays up the retro lighting and creates the room's mood. If you prefer a more contemporary room, testing various materials with a black light can help guide your choice of fabrics and decorative elements. For example, white cotton sheets and curtains tend to glow brightly when a black light is on. Creating a color scheme with white and one or two accent colors results in a simple color scheme that works with the lava lamp and black light -- yet looks natural when the lights are off.
In an eclectic decorating theme with a lava lamp and black light, combining several elements such as industrial or antique furniture with rustic, handmade framed art or Asian-inspired low seating gives you freedom to design a room personalized to your tastes, without being limited to one era or style. Bean bag chairs in the corner of the bedroom and a Mission desk decorated with a row of lava lamps in front of a mirror creates a pleasing background for your retro lights, as do a living room with chrome standing lamps fitted with black lights and a mural in neon paint above a sleek leather sofa.