Comparison of Narrow-Band Reflectance Spectrophotometric and Tristimulus Colorimetric Measurements of Skin Color

Abstract

Two types of portable reflectance instruments, tristimulus colorimeters (Chroma Meter CR-200®) and narrow-band spectro-photometers (Dermaspectrometer®), have recently become available for the quantification of skin color. In order to know the difference and the relationship between the different color systems, the CIE L*a*b* system and the erythema melanin (E/M) indices, respectively, adopted by the two, the variations in skin color were measured at 23 different anatomical sites of 10 healthy Caucasian male subjects. The reddish tint of the skin color of the face, palm and sole was readily detected by either of them in the increase in the a* value or in the E index, and a strong linear correlation (r = 0.92, p < 0.001) was noted between the two values. The fair color appearance of the trunk was detected in the high L* value and in the low M index, but the correlation between the two was much less significant (r = -0.56, p < 0.001). Although the mean b* values were highest in the trunk, they are significantly lower on the non-light-exposed side than those on the light-exposed side of the arm. The correlation between the b* value and the M index was weak.