The paper explores language-internal variation in the referential meaning of the lexical form blue. Taking a usage-based cognitive approach, it analyzs the referential range of blue in several marketing contexts from a semasiological and an onomasiological perspective. The study develops an interdisciplinary method that combines frequency analysis with mapping of the referent distributions in the three-dimensional CIELab color space. It is argued that the observed referential variation in blue is influenced by usage-related factors such as availability of the referents, diversity of color naming strategies and onomasiological competition between lexical forms in the individual product categories.