Gamut / out-of-gamut
The colors a device can reproduce. Out-of-gamut colors sit beyond that range, so conversion has to replace them with reachable ones.
See it
What it is
A gamut is the set of colors a device, ink set, or color space can reproduce. A color outside the destination gamut has no exact output value, so color management must clip it to the boundary or remap a wider group of colors to keep their relationships. Pantone 021 Orange, Reflex Blue, and the fluorescents such as 806 are the standard examples: four process inks cannot reach them, so they land duller and darker.
Reach for gamut checking before converting bright RGB artwork to a specific CMYK output profile. Adobe Photoshop's soft proof and Gamut Warning can locate risky areas, while a physical contract proof shows how the whole conversion behaves on a characterized output condition.
Gotcha: there is no single universal RGB gamut or CMYK gamut, and one is not a neat smaller copy of the other. The boundary changes with the profiles, inks, stock, and viewing conditions. A warning marks colors that need mapping; it does not predict the visual size of the shift by itself.
Ask AI for it
Soft-proof this RGB artwork in Adobe Photoshop against PSO Coated v3 (FOGRA51) with Relative Colorimetric rendering and Black Point Compensation enabled. Turn on Gamut Warning, identify every affected brand color and large flat area, and replace each with the closest in-gamut Lab color. Return a table with source Lab, proof Lab, CIEDE2000 delta E, and the final CMYK build.