Diatopic variation in the referential meaning of the "Italian blues"

Standard Italian blu is unanimously glossed as “dark blue”. In comparison, azzurro is referred to as either “light blue” or “medium blue” in different studies. We explored diatopic variation (linguistic variation on a geographical level) in the denotata of blu, azzurro and celeste “sky blue” in a psycholinguistic experiment conducted in Verona (Veneto region) and Alghero (Sardinia). Participants named Munsell chips of the BLUE area. For each blue term, a referential volume of naming-consensus colours was fitted by a convex hull visualized in CIELAB space. The referential extents of azzurro and celeste were found to differ markedly between the two regions: Verona participants used azzurro to denote “medium-and-light blue”; in contrast, for a similar colour space extent, Alghero participants used predominantly celeste, with azzurro being constrained to darker “medium blue”. The historical factors are discussed behind the more conservative colour naming in Sardinian dialects compared to mainland Standard Italian.