To polish your nails in your dream, suggests that you need to put more focus onto what you are doing and what you are trying to accomplish.
To dream that you are changing your nail polish color, represents your creativeness or emotional nature.
Look up the color of the nail polish for additional significance. In particular, to see blue, green black, purple or other non-traditional nail polish color in your dream, represents your free spirit.
You like to express yourself in unique ways.
If you see clear nail polish in your dream, then it signifies your objectiveness in a situation.