A method of determining a conversion table for colour transformation of images of biological material, comprising - preparing a first set of biological test objects using a first preparation method, the set comprising at least one test object, wherein the first preparation method comprises a first staining method; - preparing a second set of biological test objects using a second preparation method, each test object in the second set of test objects corresponding to a counterpart test object in the first set of test objects, the test object and its counterpart being of the same biological type of material, wherein the second preparation method comprises a second staining method, and wherein the first staining method differs from the second staining method; wherein the following steps are performed or controlled by computer: - for each test object in the first set of test objects, determining a colour of the test object, thereby generating a first set of colours; - for each test object in the second set of test objects, determining a colour of the test object, thereby generating a second set of colours, and characterized by the step of: - generating a conversion table indicating a mapping between the colours in the first set of colours and the corresponding colours in the second set of colours, wherein the conversion table is for colour transformation to view images of biological material in a converted colour. - preparing a first set of biological test objects using a first preparation method, the set comprising at least one test object, wherein the first preparation method comprises a first staining method; - preparing a second set of biological test objects using a second preparation method, each test object in the second set of test objects corresponding to a counterpart test object in the first set of test objects, the test object and its counterpart being of the same biological type of material, wherein the second preparation method comprises a second staining method, and wherein the first staining method differs from the second staining method; wherein the following steps are performed or controlled by computer: - for each test object in the first set of test objects, determining a colour of the test object, thereby generating a first set of colours; - for each test object in the second set of test objects, determining a colour of the test object, thereby generating a second set of colours, and characterized by the step of: - generating a conversion table indicating a mapping between the colours in the first set of colours and the corresponding colours in the second set of colours, wherein the conversion table is for colour transformation to view images of biological material in a converted colour. - for each test object in the first set of test objects, determining a colour of the test object, thereby generating a first set of colours; - for each test object in the second set of test objects, determining a colour of the test object, thereby generating a second set of colours, and characterized by the step of: - generating a conversion table indicating a mapping between the colours in the first set of colours and the corresponding colours in the second set of colours, wherein the conversion table is for colour transformation to view images of biological material in a converted colour. - generating a conversion table indicating a mapping between the colours in the first set of colours and the corresponding colours in the second set of colours, wherein the conversion table is for colour transformation to view images of biological material in a converted colour.