It’s probably the small number of colours that allow for the bottle to have no labels stuck on it at all.
Namiki and Pilot are different faces of the same entity, and they seem to slip around one another depending on time and place. Historically, on the pen side of things, Namiki are the upscale brand, and yet (at least in North America) the company’s boutique inks come out branded by Pilot. Namiki ink, on the other hand, is profoundly non-boutique, available in all the colours a sensible businessman could possibly want– blue and black!
Not a camera trick! This bottle is resting in this position, which is designed to allow filling with a mostly-empty bottle.
As with most manufacturer’s inks, this one is profoundly safe for pens. From my limited experience I think it’s an ink which expects to meet fountain pen-friendly paper, as it’s somewhat feathery.
Examples (note– I’ve not calibrated my scanner, so these are mere approximations of the true colour):
Blue: If used in a damp pen, this ink creeps toward vibrancy, but it will also veer in a grey direction on some papers. At its base, it is another of the vast crowd of standard, moderate, well-behaved blues. I understand that it is somewhat more than usually resistant to fading, but I won’t have direct experience with that for a couple of years. I do have direct experience with it being unusually, for this colour, resistant to water.