Method for producing a mixed colour by mixing a basic colour with the achromatic colour white and/or the achromatic colour black, characterized in that the mixed colour is selected from a mixed colour space and the mixed colour space is represented by a two-dimensional Cartesian coordinate system with the axes X and Y, where the axis X has values in the range from 0 to 100 and the axis Y has values in the range from 0 to 100, the coordinate represents the basic colour of the mixed colour space, the coordinate (100|0) represents the achromatic colour white, the coordinate represents the achromatic colour black and the coordinates (100-u|100-v) represent the mixed colours from the basic colour of the mixed colour space with the achromatic colour white and/or the achromatic colour black, where u has values in the range from greater than 0 to 100 and v has values in the range from greater than 0 to 100, where, if u = 100, then v ≠ 0 and 100 and if v = 100, then u ≠ 0 and 100, and where i) if v = 100 and u ≠ 100, the term (u*100)/100) corresponds to the percentage proportion of the basic colour and the term ((100-u)*100)/100 corresponds to the percentage proportion of the achromatic colour white, with respect to the sum of the proportions of and, or ii) if u = 100 and v ≠ 100, the term (v*100)/100) corresponds to the percentage proportion of the basic colour and the term ((100-v)*100)/100 corresponds to the percentage proportion of the achromatic colour black, with respect to the sum of the proportions of and, or iii) if u ≠ 100 and v ≠ 100, the term (u*v100) corresponds to the percentage proportion of the basic colour, the term ((100-u)*v/100) corresponds to the percentage proportion of the achromatic colour white and the term (100-v) corresponds to the percentage proportion of the achromatic colour black, with respect to the sum of the proportions of, and, comprising the steps of a1) selecting a mixed colour from the mixed colours with the coordinates (100-u|0), where u ≠ 0 and 100, and b1) mixing the achromatic colour white with the basic colour of the mixed colour space until the selected mixed colour from step a1) is achieved, or a2) selecting a mixed colour from the mixed colours with the coordinates (0|100-v), where v ≠ 0 and 100, and b2) mixing the basic colour of the mixed colour space with the achromatic colour black until the selected mixed colour from step a2) is achieved, or a3) selecting a mixed colour from the mixed colours with the coordinates (100-u|100-v), where u ≠ 100 and v ≠ 100, b3) mixing the achromatic colour white with the mixed colour of the mixed colour space until the mixed colour with the coordinate (100-u|0) is achieved, and c3) mixing the mixed colour from step b3) with the coordinate (100-u|0) with the achromatic colour black until the selected mixed colour from step a3) is achieved. i) if v = 100 and u ≠ 100, the term (u*100)/100) corresponds to the percentage proportion of the basic colour and the term ((100-u)*100)/100 corresponds to the percentage proportion of the achromatic colour white, with respect to the sum of the proportions of and, or ii) if u = 100 and v ≠ 100, the term (v*100)/100) corresponds to the percentage proportion of the basic colour and the term ((100-v)*100)/100 corresponds to the percentage proportion of the achromatic colour black, with respect to the sum of the proportions of and, or iii) if u ≠ 100 and v ≠ 100, the term (u*v100) corresponds to the percentage proportion of the basic colour, the term ((100-u)*v/100) corresponds to the percentage proportion of the achromatic colour white and the term (100-v) corresponds to the percentage proportion of the achromatic colour black, with respect to the sum of the proportions of, and, a1) selecting a mixed colour from the mixed colours with the coordinates (100-u|0), where u ≠ 0 and 100, and b1) mixing the achromatic colour white with the basic colour of the mixed colour space until the selected mixed colour from step a1) is achieved, a2) selecting a mixed colour from the mixed colours with the coordinates (0|100-v), where v ≠ 0 and 100, and b2) mixing the basic colour of the mixed colour space with the achromatic colour black until the selected mixed colour from step a2) is achieved, a3) selecting a mixed colour from the mixed colours with the coordinates (100-u|100-v), where u ≠ 100 and v ≠ 100, b3) mixing the achromatic colour white with the mixed colour of the mixed colour space until the mixed colour with the coordinate (100-u|0) is achieved, and c3) mixing the mixed colour from step b3) with the coordinate (100-u|0) with the achromatic colour black until the selected mixed colour from step a3) is achieved.