Hi there...I am wondering if the discoloration is particularly around your mouth? This is a common thing according to Traditional Chinese Medicine and it indicates: "A yellow colour around the mouth and lack of tone in the mouth (Fig. 8) indicate that the digestive energy is weak and a change of diet and enzymes are needed." Also, spleen qi deficiency (if your stools are on the soft side).
I got that information at the bottom of this page.