Ruling on using nail polish, and does it have to be removed when doing wudoo’
Question

                Is there any sin involved in a woman wearing nail polish? What should she do when doing wudoo?
Praise be to Allah.We do not know of any ruling on that, but 
          it is better not to use it, because there is no need for it, and because 
          it may prevent the water reaching the skin when doing wudoo’. In brief, 
          it is better not to use it, and to be content with henna, because that 
          which the earliest Muslim women used is better. If a woman does use 
          it, then she has to remove it when doing wudoo’, because – as we said 
          – it prevents the water from reaching the skin. And Allaah is the Source 
          of strength.