The object of research is composite materials based on an epoxy binder with various pigments. The purpose of the research is to substantiate the proposed methodology for analyzing the colour change of protective coatings and to evaluate the decorative properties of epoxy composites used in marine climate conditions. Method. The studied composites were aged in natural and climatic conditions in the coastal strip of the Black Sea of the city of Gelendzhik (Russia) in an open area and under a canopy. Samples were scanned at control points. The resulting images were processed in a software package based on the use of the RGB colometric system, using the compiled C# programming language on the platform .NET. Results. As a result of the tests carried out, the dependences of changes in the RGB codes of composites were established. The compositions most resistant to colour degradation were determined, which are affected by aggressive factors, such as high humidity, ultraviolet radiation, salt fog, precipitation and seasonal temperature fluctuations.