For your naturally yellow teeth you can go for bleaching
(chemical or laser
bleach). Ask your dentist
about it. Remember, any toothpaste in any form will not whiten your teeth, its only purpose is to clean the teeth and if you try hard, it will results in damaging teeth and gums. Please don't use any home remedies which often includes baking soda, lemon etc. These materials abrades the enamel so your teeth will become more stain and dirt prone. Thank you.