Nowadays many problems requiring huge computing power have risen. Although the performance of digital processors doubles every year, there are certain tasks where the computation cannot be carried out within a reasonable time interval. Such hard problems are the analysis of big dynamical systems or real-time exact colour reproduction. The exact colour visualization of motion pictures is necessary in industrial medical and scientific research areas. Thus for example exact colour reproduction is required for remote medical diagnosis or remote operation. The doctor has to see the same image that appears in reality. Device dependent colour appearance may cause faulty decisions. Nowadays these problems cannot be solved perfectly because many steps of the transformation are not completely known and the huge number of computations cannot be done in real-time even by the fastest PC. In this article we describe some methods to produce exact colours in a remote medical diagnostic system.