This work reports on the colour changes in wood surfaces, namely from the species European pine, fir, Bosnian pine, chestnut and cherry, which have been modified by a new nanoparticulate treatment. Colour values (CIE L*, a*, b*) for both control and treated wood samples have been studied for each of the five different species. The results have shown a certain effectiveness of the anti-UV surface treatment used, while lower effects were due to ultraviolet light induced photodecolouration.