SAMPLING COLOUR AND CHROMATIC CORRESPONDENCES

Colorimetric analysis, based on RGB coordinates, establishes a mathematical model for measuring color perception, allowing precise identification of chromaticity and variations on treated and untreated surfaces. Colorimeters convert colors to numerical codes following international standards, ensuring universal comprehension. In the realm of historical and artistic heritage, instrumental colorimetry has evolved with portable devices, enabling non-destructive analyses in situ. However, challenges arise when physical contact is impractical or undesirable, especially for delicate artworks. The colorimeter, connected to a computer, analyzes reflected light, providing quantitative color indications and detecting imperceptible chromatic differences. Modern colorimeters offer flexibility with RGB, CIE Lab*, and Munsell models, allowing automatic switching and expressing results accordingly. The CIELAB color-difference formula facilitates colorimetric assessments. Translation from CIELAB to RGB, HSB, CMYK, and PANTONE colors is achievable through various methods, offering essential tools for restorers and technicians engaged in digital and real restoration processes.