Color chart
A color chart is a systematic arrangement of colors or their representations, organized with respect to the attributes of the colors or the mixing relations of their stimuli, serving as a reference for selection and comparison.[1] These charts display samples of hues, often in grids or wheels, to aid in visual standardization and reproduction across mediums such as paint, print, and digital design.[2] Developed since the fifteenth century, color charts originated from efforts by physicians to classify bodily fluids like urine, and by naturalists, dyers, and painters to document pigments and dyes empirically.[3] Over time, they evolved into tools for precise color matching, with innovations in organization reflecting advances in science, commerce, and technology, from plant-based dyes to synthetic swatches.[4] In modern applications, particularly graphic design and printing, color charts like those based on CMYK process inks or proprietary systems ensure consistent output by providing measurable references for halftone reproduction and calibration.[5][6] Key characteristics include fixed color patches for empirical verification, as seen in calibration targets used in photography and imaging to correct device-specific variations in color rendering.[7] Such charts mitigate discrepancies arising from substrate differences, lighting conditions, and production processes, enabling causal reliability in color fidelity from conception to final product.[8]