But depending on how you read the term, "black light bulbs" can mean two different things: bulbs with "black light" (or blacklight blue) effects; and simple black colored lights. Not the bulb portion so much as the body of the light, which is a popular fashion trend in some settings. Often you'll find this style of lighting used in higher end homes and retail settings, potentially in monochromatic room designs like these.
If you're considering light bulbs with black design elements, you could also consider recessed lighting cans that are black inside and/or use a black trim ring.
There isn't any practical difference between these and more standard white options. They're a design choice, and one you can use to set your lighting apart from the norm.