The archive contain all datafiles used in analyses in the manuscript: Body coloration and mechanisms of colour production in Archelosauria: The case of deirocheline turtles. Specificaly there are: reflectance spectra of all individual turtles, summary variables derived from reflectance spectra of all individuals, R script of multivariate analyses of summary variables, electromicrographs of reflecting platelets of turtles' iridophores, measurements of reflecting platelets of iridophores, electromicrographs of collagen fibres used in Fourier analyses, output files resulting from Fourier analyses of collagen fibres, and description of changes in Fourier tool script provided by Dr. Prum (https://prumlab.yale.edu/research/fourier-tool-analysis-coherent-scattering-biological-nanostructures) that were necessary to secure compatibility of current versions of MATLAB.