Recently, we published a study on the hyperspectral analysis of seven-color tile images. More information can be found at the following link:

Aarab, A., Rajabi, R., Mirbaqeri, S. et al. Noninvasive analysis of Safavid dynasty seven-color (haft-rang) tiles in central Iran through hyperspectral imaging and portable XRF. Eur. Phys. J. Plus 139, 509 (2024). https://doi.org/10.1140/epjp/s13360-024-05297-7