Color gamut.

A color gamut is the set of colors one specific combination of ink, substrate and press can actually produce, measured rather than assumed. Anything outside it has to be pulled back inside that boundary before it prints, which is why an out-of-gamut orange or navy comes back flatter than the file, and why the same artwork lands differently on two garment colors. The gamut belongs to the whole system, not the printer: change the blank, the ink set or the underbase and the boundary moves with them. Shops pay for that at approval, when a customer signs off on a screen, rejects the sample and takes a remade sample plus a pushed ship date, because no amount of ink adjustment reaches a color the system was never able to make.