That's not entirely true. What you refer to UV lights are more correctly termed Black Light Bulbs, and emit UV-A light, along with a very small amount of purple light. The UV itself is not visible to the naked eye. The purple light is usually only visible on the bulb itself, as it's made out of a material called "woods glass" which is basically dark purple/black glass.
They do make "Germicidal UV Lights" That use UV-C light, which appears white, or with a very minor light blue tint depending on intensity.
Reptile Lamps are also UV lights, more specifically a mixture of some UV-A and mostly UV-B light, and it very much does appear as a bright white lamp.
Note: Most reptile lights use incandescent bulbs as opposed to the light I linked, which is a cathode based lights as incandescent bulbs also act as a heater for there cage.
I'm unsure how UV-B and UV-C light effects U.V. reactive things, or if it's at all similar to UV-A effects, but there are in fact other colored UV lights.
Edited by ZytheEKS - 9/12/13 at 11:28pm