Why might diet affect the skin color?
A new mother notices that her 6-monthby old son has a yellow-orange complexion. Fearful that the child may have jaundice (a condition caused by bilirubin, a toxic yellow-orange pigment produced during the destruction of red blood cells), she takes him to the pediatrician. After examining the child, the pediatrician declares him perfectly healthy and advises the mother to watch the child’s diet.
It is possible that a diet containing plenty of fruits and vegetables can help to alter a person's skin tone, but not really the skin color. Fruits and vegetables contain natural chemical compounds called antioxidants. These chemicals usually have complex chemical structures that allow for interesting light absorbing properties and thus lead to deep colors. One study in the link below suggests that a diet rich in a family of antioxidants called the carotenoids can lead to a more pleasing, natural looking tan complexion.
One interesting story I read on this topic just the other day talked about a medical condition called argyria where the skin turns dark blue in color due to the ingestion of silver particles. The silver particles accumulate in the skin tissues and turn dark over time upon exposure to sunlight. Interestingly, colloidal silver used to be used as an early antibiotic and general internal medicine in decades past.