Spectral photometers (or spectrophotometers) are high-quality colorimeters that can measure and accurately describe any colour.
The measuring instrument achieves this by illuminating the measuring surface with the entire spectrum of the visible light. The remission values of certain wavelengths together give the measured value, often this is output in Lab (measuring mode freely selectable from M0 to M2). The spectral measurements can also be stored directly.
High-quality proof printers have their own spectrophotometers to verify the print directly.