Re: yelow nails
try going into a public beauty supply store (such as Sally's Beauty Supply if there's one in your area) and ask them if they have a nail bleach. its not harmfull to you or your nails, its made to bring the yellow staining off of your nails. I found this works really well with myself doing hair coloring at work and having my nails done with a french manicure, they always get stained with hair color....plus smoking cigarettes doesn't help much....but the nail bleach works wonders!! i have also heard that lemon water will help a little bit, but not as much as bleach.