Hello, I have calculated delta E 2000 from the colprof output (option -y) in a spreadsheet and with Bruce Lindbloom's web-based calculator: http://www.ece.rochester.edu/~gsharma/ciede2000/dataNprograms/CIEDE2000.xls http://www.brucelindbloom.com/index.html?ColorDifferenceCalcHelp.html Both of the above are consistent but colprof's delta E values are different and do not match DE76 and DE94 either. Which delta E is colprof reporting? The documentation states only that "a summary of the average and maximum Lab delta E's will be printed out if this flag [-y] is set". Is colprof applying any weighting to the DE00 calculation: KL, KC, KH not equal to 1.0? Stephen.