Some people have certain substances in their sweat that can make the sweat appear in different colors such as yellow, yellow-brown, green, cyan, red or black, clinically known as chromatophobia. Most of them do not cause any symptoms, but in very few cases the skin can be seriously contaminated. These areas are often not the normal distribution areas of the sweat glands, but the places where ectopic sweat glands exist, such as the face, and the color can be yellow, blue, cyan, purple, brown and black, etc. Yellow is the most common, and rarely red. The diagnosis of color sweating can be based on clinical symptoms: 1. It can occur at any age, and can be persistent or intermittent. 2.More often seen in the face (not the area of normal sweat gland distribution, but where ectopic sweat glands exist), followed by the armpits, umbilicus and vulva. The color of sweat varies, with yellow being the most common, and yellow sweat in the armpits is often combined with axillary odor. Sweat glands secrete blue or green color, such as injection of methylene blue can be cyan sweat, iodide can make sweat light red, internal clofazimine (chlorpheniramine) can make sweat red. The next can also be seen brown, black, purple, brown, also with the development of blood color is called blood sweat (hematohidrois). Blue sweat, green sweat can be seen in workers engaged in the copper industry.