Method for the computer-aided execution of transformations of colour data from a source colour space into a target colour space using a given transformation rule TRV, wherein the source colour space comprises n colours which are present in each dot to be printed in combinations of colour proportions q to q(n), the target colour space comprises m values which can be combined to form combinations of components z to z(m), and there are at least some combinations of the colour components q, q,..., q(n) of the source colour space, for which combinations of components z, z,..., z(m) of the target colour space are assigned, characterised by the following steps: a) selecting a set of colour data Q1 of the n colours of the source colour space with the colour components q, q,..., q(n), for which there is a set of target value data Z1 in the form of combinations of components z, z,..., z(m) of the target colour space; b) generating a second set of colour data Q2 of the n colours of the source colour space with the colour components q', q',..., q'(n), which are initially set identically to Q1; c) transforming the set of colour data Q2 using the transformation rule TRV to generate an actual value data set Z2 of the m values of the target colour space z', z',..., z'(m); d) applying an n-dimensional optimisation method which, by suitably modifying the set of colour data Q2 and repeating step c), minimises the differences between target value data set Z1 and actual value data set Z2 in terms of the least squares error, so that Q2 finally contains the resulting optimised colour components q', q',..., q'(n); e) calculating the differences Dq = q' -q, Dq = q' -q,..., Dq(n) = q'(n)-q(n) of each colour component of the n colours of the optimised colour data set Q2 to the respective colour component of the colour data set Q1; f) calculating the differences Dz = z -z', Dz = z -z',..., Dz(m) = z(m)-z'(m) of each component of the colour data set Z1 to the respective component of the colour data set Z2; g) applying the differences Dq, Dq,..., Dq(n) and Dz, Dz,..., Dz(m) when transforming sets of colour data from the source colour space with n colours to the m values of the target colour space by adding the difference Dq(i) to the colour data q(i) of the n colours of the source colour space for the i=1 to n values when transforming a data set, the colour data q'(i) modified in this way are transformed into the m components z'(j) for the j = 1 to m values of the target colour space using the transformation rule TRV and then the corresponding difference Dz(j) is added to the respective component z'(j). wherein the source colour space comprises n colours which are present in each dot to be printed in combinations of colour proportions q to q(n), the target colour space comprises m values which can be combined to form combinations of components z to z(m), and there are at least some combinations of the colour components q, q,..., q(n) of the source colour space, for which combinations of components z, z,..., z(m) of the target colour space are assigned, a) selecting a set of colour data Q1 of the n colours of the source colour space with the colour components q, q,..., q(n), for which there is a set of target value data Z1 in the form of combinations of components z, z,..., z(m) of the target colour space; b) generating a second set of colour data Q2 of the n colours of the source colour space with the colour components q', q',..., q'(n), which are initially set identically to Q1; c) transforming the set of colour data Q2 using the transformation rule TRV to generate an actual value data set Z2 of the m values of the target colour space z', z',..., z'(m); d) applying an n-dimensional optimisation method which, by suitably modifying the set of colour data Q2 and repeating step c), minimises the differences between target value data set Z1 and actual value data set Z2 in terms of the least squares error, so that Q2 finally contains the resulting optimised colour components q', q',..., q'(n); e) calculating the differences Dq = q' -q, Dq = q' -q,..., Dq(n) = q'(n)-q(n) of each colour component of the n colours of the optimised colour data set Q2 to the respective colour component of the colour data set Q1; f) calculating the differences Dz = z -z', Dz = z -z',..., Dz(m) = z(m)-z'(m) of each component of the colour data set Z1 to the respective component of the colour data set Z2; g) applying the differences Dq, Dq,..., Dq(n) and Dz, Dz,..., Dz(m) when transforming sets of colour data from the source colour space with n colours to the m values of the target colour space by adding the difference Dq(i) to the colour data q(i) of the n colours of the source colour space for the i=1 to n values when transforming a data set, the colour data q'(i) modified in this way are transformed into the m components z'(j) for the j = 1 to m values of the target colour space using the transformation rule TRV and then the corresponding difference Dz(j) is added to the respective component z'(j).