When the bottoms of your feet are yellow, this can be a sign of either a bacterial or fungi infection. Try to find a good antifungal cream and rub into the bottoms of your feet, often this will help. Do you feet have a distinct odor?
If the antifungal cream doesn’t help at all, yellow feet can mean a number of different things; adrenal problems, hypothyroidism, anemia, or hepatitis since liver problems can cause you to have yellowish body parts or even over your whole body. You might consider having your liver tested if the antifungal cream fails to make a difference.