I am a 25 yr old indian female and I have developed dark black lips in the recent 2 years, esp the upper lip.earlier they were pink.I dont smoke and i drink tea with milk twice a day.My diet is proper and i do drink lots of water as well. I would like to know what causes the lips to darken,are there any creams or medicines or natural therapies available to get back my original lip color, and do i restore my lip color in the future.Could you also suggest the type of lip balm or lipticks that need to be used for sensitive lips.would appreciate your reply.