Yellow discoloration of a child's soles may be caused by a diet rich in carotenoids and vegetables, according to the Indian Journal of Endocrinology and Metabolism. Changes in blood sugar in patients with diabetes may also cause skin discoloration on the feet.
Yellow colored skin on the feet is also associated with hypothyroidism, a condition where the body produces too much of the thyroid hormone, liver disease, renal disease and hyperlipoproteinemia, according to the Russian Open Medical Journal.
Xanthoderma, also known as carotenemia, is a common condition in children with an excessive consumption of carrots, squash and sweet potatoes, according to Medscape. The condition is characterized by yellow skin pigmentation and is harmless for those affected.