Color naming across languages has traditionally been held to reflect the structure of color perception. At the same time, it has often, and increasingly, been suggested that color naming may be shaped by patterns of communicative need. However, much remains unknown about the factors involved in communicative need, how need interacts with perception, and how this interaction may shape color naming. Here, we engage these open questions by building on general information-theoretic principles. We present a systematic evaluation of several factors that may reflect need, and that have been proposed in the literature: capacity constraints, linguistic usage, and the visual environment. Our analysis suggests that communicative need in color naming is reflected more directly by capacity constraints and linguistic usage than it is by the statistics of the visual environment.