One hundred and twenty children from each of four cultural groups (Australian, Japanese, Greek and Greek/Australian) and ranging in age from 4 to 7 years were required to name twenty colours, these being the most saturated hues from the Munsell chart. Reliable differences were found in the mean speed of response by the groups and there were seen as being related to speed of lexical search. Specific difficulties in naming were associated with stimuli located at the overlap of colour categories but the Japanese showed increasing use with age of a specific term to cope with one of these areas of overlap. The other national groups employed a large number of qualifying terms to handle "gaps" in the psychological colour solid. The developmental evidence pointed to the role of education in hastening the acquisition of appropriate colour term.