The shape of the nail tells you the state of the body, so does the color of the nail. Fingertips are the most distant area from the center of the body, and because there are fine and narrow area, the disorder of qi of the body appears there promptly.
The color of nail plates is light pink, there is a white lunula in the matrix, and no specific color appears in the skin around the nail bed; these are the good condition of the nail. For, light pink color and white moon indicate energy of qi in the body, and dark color around the nail matrix means stagnation of qi.
*This article is translated from "Yamai hitokuchi Memo" written by Shoji Kobayashi, 2005.