The analysis of metameric blue fibers and their forensic significance.

Metamerism is a phenomenon where two or more colored items with different colorant chemistries appear to the observer to be the same color. Those differences should result in different UV-visible spectra. Additionally, the literature on color science states that metameric samples will have spectra that intersect at three or more loci. Metameric samples of blue textile fibers, which were created using different coloring agents or different relative concentrations of the coloring agents, were studied to demonstrate that they could be differentiated by obtaining their spectra between 350 and 800 nm using UV-visible microspectrophotometry. However, while some of the metameric samples tested did intersect at three or more loci, others did not intersect at all. In the spectra that did intersect, no correlation was found between either the dye chemistries or the relative component concentrations.