Try soaking your names in lemon juice. You can add a bit of sugar too to make a scrub if the stains are particularly stubborn. Might need to do it a couple of times but it worked for me. Good luck.
If it is due to the nailvarnish that you have removed yesterday then try Barbara Daly Goodbye Yellow clear varnish - they sell it in Tescos for about £5 - works like a dream for me ....