Marketing - it's a hell of a drug.
Ok, but seriously, it's almost definitely not actually UV like a tanning bed. Most of the time they limit the bandwidth very specifically (forgot the range) so it's actually only just barely in the UV range, mostly it's purple.
As for the black... couldn't say. I'd have to see the fan I guess. The fan housing and the fan itself are very different... probably the housing is just plain black plastic and the fan blades are UV reactive.