Assessment of Colour Differences in Silicone Hand and Digit Prostheses: Perceptible and Acceptable Thresholds for Fair and Dark Skin Shades

This study addresses the dilemma of initial clinical and social acceptance of a newly fabricated silicone prosthesis in relation to its colour match to the natural skin. This was achieved by derivation of specific colour difference thresholds defining perceptible and acceptable levels of colour sensitivity. Two separate sets of 10 fair and dark shade digit prosthesis samples were each fabricated with a stepped increase in colour difference (ΔE) against the baseline hand prosthesis. Ninety individuals with normal colour vision scores were selected as colour assessors. The colour difference of each prosthesis in the two series was evaluated visually against the baseline by the assessors, using defined scores. The thresholds for perceptible and acceptable colour difference determined in this study were ΔE = 0.8 and ΔE = 1.8 for the fair series and ΔE = 1.3 and ΔE = 2.6 for the dark series, respectively. The acceptable threshold values differed from the perceptible threshold values by ΔE = 1.0 for the fair-sh...