if the color used is สีละลายน้ำ Let's test it first. whether stable in the product of the member or not Due to the many colors such as blue, commonly used in mouthwash products. it has good stability Therefore, it may not be necessary to use a stabilizer.in case of mouthwash put Color must be entered Protec™ UV ( Benzotriazolyl Dodecyl p-Cresol ) Additional 0.10% amount to prevent color change