Is Bottled Namiki Blue (or Black) Ink the Same Ink as the Pilot Blue (or Black) Cartridges?

I'm currently pondering this mystery and will continue updating this page with what I find.

In swatches, the blue inks look almost the same (the Pilot Blue cartridge ink is sliiightly lighter than the Namiki Blue), but the Pilot Black looks markedly lighter than the Namiki Black.

For now I'm still blaming batch-to-batch differences and problems with my own testing/methodology - I have a truly hard time believing that these inks have any reason to be different on Pilot's side.

I'll do some water resistance tests tomorrow.