Résumé
Either for visual evaluation or image analysis, a color selection chart allow for a more accurate and repeatable color quantification. Commercial color reference chart exist but covers a wide range of colors, making it harder to evaluate the desired object color. The present SOP describe step by step how to implement its own customized color reference chart and propose an R script automatizing the process. The creation of a color reference chart relies first on the extraction of typical colors from a collection of available numeric images covering the range of desired product color variation. This palette of color is then characterized in different color spaces, plotted on a chart and printed. Finally, the correspondence between the desired color value and the printed chart is verified using a chromameter.