A Comparison of Macroscopic and Microscopic Hair Color Measurements and a Quantification of the Relationship between Hair Color and Thickness

Abstract Microscopic images of hair from 36 individuals were evaluated for color (using the CIE L * a * b * color space), hair thickness, and the pattern of pigmentation. These measurements were compared to each other and to reflective spectrophotometric measurements of macroscopic hair color. Three areas on three strands of hair were examined for each individual. Despite a large Δ E * value, there is a strong relationship between macroscopic and microscopic L * values that would be useful if one was trying to predict the color of a head of hair (macroscopic) from a strand (microscopic). A relationship between hair lightness ( L *) and thickness is also found at both the macroscopic and microscopic levels. The information acquired in this study may be useful to those conducting a microscopic examination of hair, especially in forensic science, as well as those researchers investigating macroscopic hair color and hair morphology for the purposes of forensic science, anthropology, and medical science. Further investigation into objectively measuring and quantifying the microscopic color and properties of hair will assist in increasing its validity as evidence in forensic casework.