We often receive feedback from users who had concerns about the color of Herbal Oil. Do be assured that this color is not from any dye used but comes from the natural herb, Rhubarb (大黄), one of the main ingredients in the product. Rhubarb is a common herb used in traditional Chinese herbal medicine. It has strong anti-infection and anti-inflammatory properties, clears damp-heat and reduces fire in the body. In TCM, Rhubarb is used for the relief of swelling, sores, bruises and burns.