Recent developments in digital display technology have opened a wide range of possibilities for biomedical imaging. The opportunity to use colour is an important feature of video-display systems in clinical practice. Colour coding of biomedical data is a complex matter, which, however, may lead in many cases to an enhanced diagnostic interpretation of the images displayed. In the paper procedures for colour mapping are described and illustrated by three practical examples in the fields of scintigraphy, electrocardiography and neurophysiology. The results show an extensive applicability for colour representation of biomedical data, provided the mapping procedures are carefully selected.