Spectrophotometry The "gold standard" method of assessing skin pigmentation is reflectance spectrophotometry (RS). Pershing et al performed seminal research comparing the area under the curve obtained by RS to profile the constitutive skin color with clinicians' assessment of SPT. For skin types I-III, Pershing et al (2008) found inconsistency between clinicians' and reflectance spectrophotometric (RS) assessments of SPT. The clinicians adjusted the patients' SPT as determined by their historical sun burning and tanning response by factoring in observed hair and eye color. For example, red-haired individuals determined by RS to be SPT III were listed as SPT I by clinical dermatologists. Subjective assessment of SPT by clinicians was heavily influenced by patients' hair and eye color. The Pershing study, which accrued 125 subjects did not accrue sufficient numbers of subjects with skin of color (Skin types III-VI) to be able to report meaningful results. (I 20; II 53, III 21, IV 10, V 16, VI 5)