The color research has much interest in exploring emotional responses to color stimuli, which are referred to as color emotions. In general, color emotions are measured through psychological methods and represented as values on rating scales. For further understanding of color emotions and development of their effective application, conceptual structure of color emotions and rating scales need to be shared among various disciplinary fields. One typical approach in sharing such knowledge is to clarify concepts as an ontology. In this paper, we specified color emotions based on psychological attributes and built an ontology with an ontology development environment Hozo and a top-level ontology YAMATO. As a result, our ontology describes 16 psychological attributes which are measured by rating scales on the basis of a concept of human awareness. Approximately 74.7 percent of instances of the psychological attributes, which are frequently used in articles on measurement of color emotions, are accounted by the 16 psychological attributes. By adding descriptions of psychological attributes which are infrequently used and have not been fully elucidate in the color research, our ontology would increase utility for knowledge sharing and be feasible in prompting scientific and engineered approaches to understand human mind.