Abstract: A colour selection system is provided which comprises a memory for storing grouping information which categorises each of a plurality of colours into one of a plurality of colour groups. In response to an initial colour selection made by a user, the system determines the group in which the selected colour belongs and generates a selection of colours, using colours which belong to the determined group, from which a user can select one or more further colour in addition to the initially selected colour. The groups of colours are chosen so that the user can only select colours which are deemed to be “harmonious” with each other.