In order to replance systhetic colors by natural colors as food additive, properties of Gardenia yellow color and Gardenia blue color were compared with Food yellow No. 4 and Food blue No. 1. Color differeance between Food yellow No. 4 and Gardenia yellow color was 7.55. Thermal stability of Food yellow No. 4 was above 99%. On the other hand, in case of Gardenia yellow color, showed adove 90% of residual color units in 8$0^{circ}C$$ imes$30min and 10$0^{circ}C$$ imes$30min at pH 7.0 but 75% in 121$^{circ}C$$ imes$15min. Difference of light stability between Food yellow No. 4 and gardenia yellow color was about 18%. Addition of ascorbic acid was increased about 6% in light stability. Color difference between Food blue No. 2 and Gardenia blue color was 107. Thermal stability of Food blue No. 2 was above 99%. But Gardenia blue color showed 92% of residual color units in 8$0^{circ}C$$ imes$30min and 10$0^{circ}C$$ imes$30min at pH 7.0 but 90% in 121$^{circ}C$$ imes$15min. Difference of light stability between Food blue No. 4 and Gardenia blue color was about 8%. Addition of -tocopherol was increased about 4% in light stability of Gardenia blue color.