“…In each three‐dye recipe ( c 1 , c 2 , c 3 ) considered, the perturbations Δ c 1 , Δ c 2 , Δ c 3 of the initial dye concentrations c 1 , c 2 , c 3 corresponding to a 1.7% strength error were determined: Δ c 1 = 0.017 c 1 , Δ c 2 = 0.017 c 2 , Δ c 3 = 0.017 c 3 . The dye concentrations c 1 , c 2 , c 3 in the recipe were simultaneously changed according to the pattern (see Table 2 in Part 1 [4]) to get 27 different combinations of perturbations Δ c i , i = 1, 2, 3. The 27 colour changes and corresponding CMC(2:1) colour differences Δ E k ,pred resulting from this pattern were predicted.…”