Popular opinions link colours and emotions. Yet, affective connotations to colours are heterogeneous (e.g. red represents anger and love) partly because they relate to different contexts. Despite insufficient evidence, colours are used in applied settings (health, marketing, etc.) for their supposed effects on cognitive and affective functioning. Summarizing the literature, we invite for systematic research to investigate when and how colours link with affective phenomena. We need to i) distinguish between situations in which colours are physically shown or linguistically treated, ii) specify types of affective processes (e.g. emotion, mood, preference), and iii) investigate cross-cultural differences. Having these needs in mind, we initiated an international online survey on semantic colour-emotion associations. We outline theoretical considerations and present the survey’s design.