According to Berlin & Kay’s [5] theory, it is possible for a language to include more than 11 basic colour terms. It is remarkable that in certain languages more than one term denote "blue". Russian is a good example of a language having two basic terms for blue – sinij (dark blue) and goluboj (light blue). Similar examples of languages with two basic colour terms for blue are Turkish, Arabian, Italian and Chinese. In addition, Androulaki et al. [2] claim that Modern Greek has 12 basic colour terms, supporting that γalбzjo (light blue) should be included in these terms. The question arising is whether the term γalбzjo in Modern Greek could be considered as a basic colour term. This is the main issue in the present experimental research. For conducting the experiment the Munsell colour system was used. The results of the empirical research show that the term γalanу is a lighter hue of blй (blue) in relation to γalбzjo. Moreover, these terms cannot be considered as basic, since, on the one hand, they are included in a basic colour category (blй), and, on the other hand, they occur only in particular collocations, violating the corresponding Berlin & Kay’s (5, P. 6) criteria.