Color Technology in Printing

Basic Course (5) Color Difference

Abstract

The color difference ΔE is expressed as the distance of two colors in the three dimentional color spaces. Many color scholars has devised UCS diagrams and color difference formulae to calculate ΔE. UCS (Uniform-Chromaticity Scale) is such a diagram; the chromaticity coordinate values of the Munsell Color Swatches are plotted with equal interval spaces. Four formulae are now used by the Japanese Industrial Standards: (1) the CIE-1976 L*a*b*, (2) the CIE-1976 L*u*v*, (3) the Adams-Nickerson's and (4) the Hunter's.