The present invention relates to a use of natural pigment as nail polish pigment, which mainly comprises a violacein and a nail polish, wherein the nail polish is formed by mixing ethyl cellulose, epoxy resins, camphora, and alcohol in proportions. Accordingly, when the natural pigment of violacein that is extracted from purple color bacilli are utilized, in conjunction with a low pollution solvent system in the manufacturing process of nail polish, a healthy and environmentally friendly nail polish pigment can be developed.本發明係一種天然色素作為指甲油色料之用途,主要係由一紫色桿菌素及一指甲油所組成,其中該指甲油係由乙基纖維素、環氧樹脂、樟腦及酒精依比例所混合而成,藉此,利用紫色桿菌萃取的天然色素-紫色桿菌素,搭配低污染的溶劑系統運用於指甲油之製程,發展出健康又環保的友善指甲油色素。10‧‧‧菌液的培養20‧‧‧紫色桿菌素的萃取30‧‧‧紫色桿菌素產量的測定40‧‧‧不同精油與紫色桿菌素相溶性之測試50‧‧‧指甲油配方之測試60‧‧‧混合紫色桿菌素與指甲油與精油