The language of perception in Siwu, a Kwa language of eastern Ghana, is described based on linguistic elicitation, ethnographic field research, and a standardised set of stimuli targeting the perceptual domains of Colour, Shape, Sound, Touch, Taste, and Smell. Verbs of perception pattern into active-explorative and passive-inchoative construals of sensing. Percepts are sometimes encoded by stative verbs or nominal concepts but most often by ideophones. Colour is not a culturally salient category and Siwu may represent an intermediate type of ‘non-partition’ system, in which the available terms do not cover the colour space exhaustively. High codability in the domains of Touch and Taste appears to be associated with the availability of ideophones with highly precise meanings, while lower codability in the domain of Smell is associated with a lack of conventionalised vocabulary.