Printed colour is measured with X-Rite color measurement devices against your approved sample and file, alongside visual checks under a colour-matching light booth. BOYA is ONE (formerly GMI) certified for lithographic offset, process and spot colour. We do not promise a fixed colour-difference (ΔE) value; the achievable match depends on paper, coating and lamination, so the final reference is the sample you approve. Photo: reference image, not taken at BOYA. Ra Boe, CC BY-SA 2.5 (https://creativecommons.org/licenses/by-sa/2.5), via Wikimedia Commons (https://commons.wikimedia.org/wiki/File:Spektralfotometer_Eye-One_iO_der_Firma_X-Rit_2007_by-NRaBoe.jpg).