Tongue color refers to the color of the tongue body. According to Traditional Chinese Medicine (TCM) tongue diagnosis theory, tongue color is generally categorized into pale, light red, red, deep red (crimson), purple, and blue. Essentially, it can be divided into two main groups: This classification method serves as the most fundamental and intuitive basis for observation in TCM tongue diagnosis. Why Can Tongue Color Indicate Disease? A normal tongue color is typically light red, as the tongue is a muscular organ containing myoglobin in its cytoplasm. Additionally, its connective tissue is rich in capillaries, ensuring an abundant blood supply….