EVALUATION OF SKIN COLOR 9 values were 1.8 0.9 0.7 for L*, u*, v* respectively. This increase in standard deviations was confirmed by measurement of the Munsell standards with increasing color saturation. The magnitude of normal variation caused by time and precision of measurements, was registered in one subject by means of 9 measurements, in the zygoma area, three every hour during morningtime. The standard deviations were 1.9 0.6 0.8 for L*, u*, v* respectively. The skin color measurements of 100 subjects demonstrate an approximately normal distribution of the color indices of the forearm, the palm and the cheek. In Figure 4 these distributions are shown for u*. The means and standard deviations of u*, v*, L* indices oeor the three measured skin areas are shown in Table III. Only for the palm and the cheek is the difference for the mean u* between females and 1.0 0.5 0 cumul. freq. arm cheek total 0 10 20 2'5 3'0 • u '• Figure 4. The relative u* color coordinates for the inner side of the forearm, the thenar palm of the hand and infra-orbital area of the cheek are approximately normally distributed over the populations.

10 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Table III Means and Standard Deviations (Denoted with S.D.) of the Sample (Values Corrected to Munsell Standards) N L* S.D.L, u* S.D.,, v* S.D. e Inner Forearm: Male 48 57.0 5.9 10.2 2.1 13.0 2.4 Female 51 56.1 5.3 9.5 2.1 12.2 2.3 Total 99 56.5 5.6 9.8 2.1 12.6 2.3 Palm: Male 49 51.4 5.0 11.9 2.4 9.6 2.1 Female 51 52.7 5.2 10.8 2.3 9.9 2.2 Total 100 51.8 5.2 11.4 2.4 9.7 2.1 Cheek: Male 49 45.8 7.3 17.4 3.6 10.5 2.3 Female 51 47.2 7.5 15.8 3.0 10.8 4.2 Total 100 46.5 7.4 16.6 3.4 10.7 3•4 25 20- 15- 10 5 U* [] [300 0[3 [] [] 0 ' 2'0 ' 4'0 ' 6'0 ' 8'0 •age(y) Figure 5. Scatter diagram of u* versus age of the inner forearm ß and the cheek []. A weak correlation is present.