Take a look at the remote phosphor LED-Lamps, if you remove the yellow cap, you get a deep blue.
These royal blue wavelengths can excite some fluorescent orange and fluorescent pink pigments.
The human eye has a lower sensitivity to the deep blue wavelengths (440nm), and the eye's lens has difficulty focusing them (which is why it appears a little blurry). 440nm does appear very violet in color, but still a little more blue than true violet wavelengths, because shorter wavelengths activate the red color receptors in the eye to some extent (this is why violet appears a little purple-colored).
So a blue emitter can sort of function as a "black light" to some extent, but not very well.
