By exploring the associations that people make between emotions and colours, looking at how they vary across languages, and exploring the explanations that people provide for the associations that they make, this Element provides insight into the ways in which humans express emotions through colour, and the reasons why they do so. Metaphoric (and metonymic) language and thought play a key role on several levels in the formation of emotion-colour associations, interacting with physical, environmental and social factors. A strong metaphorical connection between the valence of the emotion and the lightness of the colours with which it is associated, and between the intensity of an emotion and the saturation level of the colours with which it is associated is found. However, the strength of this association varies according to the linguistic background of the speaker, and the gender in which the emotion is presented.