Is light blue (azzurro) color name universal in the Italian language?

In the study of 1969 Berlin and Kay have argued that there are a limited number of universal "basic color terms" which are the same for each culture [1]. They postulate the existence of 11 basic color terms, including a single blue term. After Berlin and Kay's work, several researcher have tried to confirm or refuse this theory. Those successive studies led to two principal theories: universalistic [2] (confirming the Berlin and Key theory) and relativistic (refusing the Berlin and Key hypothesis) theories [3-6]. This papers brings a new argument in favor of the relativistic theory and provides some evidence on the existence of a twelfth color class in the Italian language. In particular, results support the hypothesis of the existence of an additional monoleximic color name for the class corresponding to light blue (azzurro in Italian language). This hypothesis is proved by using the Stroop effect, introduced in 1953 by John Ridley Stroop [7]. The Stroop effect is based on the analysis of the reaction time in a given task. Our claim is that when the name of a color (e.g., "blue," "green," or "red") is printed in a color which is not denoted by the name (e.g., the word "red" printed in blue ink instead of red ink), naming the color of the word takes longer and is more prone to errors than when the color of the ink matches the name of the color. Accordingly, we investigated the reaction time of Italian mother language speakers performing a Stroop task with both dark blue and light blue color. Results show that the reaction time is statistically different when the light blue is associated to the monoleximic color name azzurro than to monoleximic color name blue (blu in Italian language).