Whitish or yellowish nails can occur due to onycholysis. This means separation of the nail from the nail bed. The color you see is air beneath the nail. The treatment is to trim the nail short, don't clean under it, polish if you want to hide the color, and wait two to three months. Persistent onycholysis can make the nails susceptible to fungal infection.
For this treatment, the affected toe or finger first has to be soaked in warm water for ten minutes and then dried. After that, the urea-based cream is applied to the nail, and the nail is covered with an adhesive bandage. After 24 hours, the bandage is removed and the toe or finger is held in warm water again. The softened layer of the nail is then scraped off using a spatula, the cream is applied again and the nail is covered with a new bandage. This treatment is carried out over 14 days. Once the infected part of the nail has been scraped away completely, the skin beneath is treated for another four weeks with a bifonazole cream.
Use soap and water to wash your feet, and dry well, including between toes. Trim your toenails -- straight across -- to keep them shorter than the end of your toe. Make sure the tools you use are clean, too. Wash clippers and files with soap and water, then wipe with rubbing alcohol. You might be tempted to cover up discolored nails with polish, but don't. Your nail bed can't "breathe," which keeps fungus from going away.