Characterization of the evolution of indigo blue by multispectral imaging Tello Burgos, Natalia López Montes, Ana María Valero Benito, Eva María Nieves Gómez, Juan Luis Blanc García, María Rosario Artificial aging Capillary electrophoresis Indigo Multispectral imaging Principal components FEDER/Junta de Andalucia-Consejeria de Economia y Conocimiento, Grant/Award Number: A-HUM-164-UGR18; Ministry of Economy and Competitiveness of Spain, Grant/Award Number: DPI2015-64571-R; Spanish Ministry of Economy and Competitiveness, Grant/Award Number: Ramon y Cajal program; Ministry of Economy and Competitiveness; Junta de Andalucia; FEDER (European Regional Development Fund). Indigo blue is a natural organic color from the Indigofera tinctoria plant. It is insoluble in water and does not require mordant to fix the color; therefore, due to its nature it can be considered as a pigment or dye. The identification of indigo in cultural heritage is very difficult due to the complexity of its chemical formula and the changes that it can undergo in certain conservation and exposition conditions. For this reason, characterization of possible degradation, transformation, and reaction processes is essential for its identification. In this study, multispectral imaging has been used for the first time as noninvasive technique to characterize the aging state of indigo blue using samples aged in a controlled climate chamber under extreme conditions of humidity, temperature, and light. The technique has proven to be very promising for this application, together with classification techniques based on machine learning approaches. 2021-10-01T10:28:57Z 2021-10-01T10:28:57Z 2021-08-14 journal article Tello Burgos, N... [et al.]. Characterization of the evolution of indigo blue by multispectral imaging. Color Res Appl. 2021; 1- 12. [https://doi.org/10.1002/col.22721] http://hdl.handle.net/10481/70572 10.1002/col.22721 eng http://creativecommons.org/licenses/by-nc-nd/3.0/es/ open access Atribución-NoComercial-SinDerivadas 3.0 España John Wiley & Sons