A color conveys a lot of meanings through language in our daily life. Such connotation of the color term arises from meaning extension of it, and the meaning extension of it is realized through our cognitive process. For this reason, this paper aims to analyze the connotation of the color term ‘red’ in various contexts and figure out the cognitive process of its meaning extension by elaborating how our cognitive mechanisms are combined and work in depth. In addition, this paper provides the characteristics of the meaning extension of the color term ‘red’ and verifies that it is not arbitrary but motivated by primarily human physical experience, along with social and cultural experience.