What is the best remedy for yellow toe nails?

Not an easy answer: Yellow toenails may be caused by fungus under the nail. Treatment is possible but takes a long time. I would see a podiatrist and have your nails examined to confirm that it is fungus, generally done with a culture of the nail. Treatment can be oral medication, topical antifungual medicine, laser treatment or permanent removal of the nail. Reocuurance is common.

Should determine if : The discoloration is secondary to a fungus. If so antifungal, if not see if nail discoloration is from nail polish or nail bed keratinization, if so a nail bed keratolytic agent may be helpful.