Determining Tolerance Values of Instrumentally Measured Color Differences to Evaluate Black Filament Yarns

There are many factors affecting the tolerance values of instrumentally measured color differences, including variety of industries, type of products to be matched with the original samples, the need of customers, etc. Regarding the insufficiency of various color difference formulae to deal with the acceptability of color matching of reproduced samples with the target, some researchers tried to present an instrumental color tolerance limit in accordance with the results of visual assessment experiments. Considering the specific colorimetric attributes of achromatic samples (with low lightness and chroma values), it was tried to set an instrumental tolerance limit based on the measured and visually perceived color differences between 20 filament black yarns and the reference one. The results showed that determining the color tolerance value based on various color difference formulae, i.e. ΔEa*b*, CIE94, CIE2000 and CMC (2:1), results in different instrumental wrong decisions, while the ΔE*ab color difference equation with the color tolerance value of 0.5 for filament black yarns showed the minimum number of wrong decisions.