In this study, Seolgi Tteok was made in order to increase consumption of Geuk, which possesses numerous nutritional advantages, and its optimum content as a new food coloring for rice cake was determined. Quality characteristics and quantitative description analysis (QDA) of Seolgi Tteok, in which Geuk was added at 0, 4, 8, and 12%, was conducted. Consumer acceptability test was also conducted. As the amount of added Geuk increased, moisture content of Seolgi Tteok increased as well. Brightness (L-value) was the highest in the control group, and more Geuk resulted in higher values of red index (a-value) and yellow index (b-value), which corresponded to the results of the sensory evaluation. As result of the mechanical texture measurement, only adhesiveness and resilience show a significant difference. As a result of the QDA, 17 sensory characteristic terms were assessed. Among them, only 13 showed a significant difference. Among the different sensory characteristics, almost all of them except for taste characteristics were significantly influenced by the amount of Geuk. The aroma and taste of Geuk were not largely influenced. It can be suggested that Geuk is not a factor that strongly influences flavor. In conclusion, Geuk does not have a strong influence on the taste or aroma of Seolgi Tteok but does on color characteristics. It can be suggested that Geuk is qualified as a coloring material for food, and the reasonable addition amount is 8%. As a result of this research, Geuk can be considered as a coloring material for other types of rice cake, traditional Korean sweets, and even confectioneries as well as for Seolgi Tteok. This implies that Geuk can be utilized to develop various new products as a coloring material with abundant nutritional content, which will contribute to the promotion of Geuk consumption.