Two Color Bulbs

The most famous of the multiple colored lamps is based on the Dual Sun™ technology by Light Sources, Inc. Several other companies use or have licenced this technology (ie: SunMaster Dual Zone™) for use in their tanning beds.

Example of a two colored lamp, in this case, the SunMaster Pro Body tanning bulb.

On the outside, these are ordinary lamps, typically in size F71/100 watt, although there are some examples in F73. What makes them different is the way that the phosphors are coated inside the lamp. Normally, a glass tube is simply flooded with a solution that has the special phosphors, then it is heat cured to make it stick to the inside of the lamp. In lamps that use two colors, the lamp is instead placed in a special jig straight up and down, and the liquid phosphor mixture is filled inside the lamp from the BOTTOM until it reaches a predetermined height. It is then drained and allowed to dry. Then the lamp is inverted, and a second mixture is used to coat the uncoated section of the lamp, until the two coatings barely overlap. Then the entire lamp coating is cured. This means that the two sections have different ultraviolet output.

Another example, this bulb is used for adding more power to the face area when used in the top of a tanning bed.

They typically add color phosphors that make part of the lamp blue and part of the lamp pink, but this is an added color that is used only to identify which parts of the lamp are 5% and which are 6.5%. The color itself doesn't affect the UV output.