The problem of colour naming consists of successfully recognizing, categorising and labeling colours. This paper presents a colour naming theory based on a Qualitative Colour Description (QCD) model, which is validated here by an experiment carried out by real users in order to determine whether the QCD model is close enough to common human colour understanding. Then, this paper presents the necessity to customize this QCD by means of a user profile, since different users may perceive colours differently because of different cultures, knowledge, experiences and even physiology. A standard QCD model adaptable to users could improve colour reference and grounding in human-machine communication situations.