In books, if women are described as wearing nail polish, it's either a demure French manicure (to show that they're rich or sophisticated) or scarlet to indicate their sex appeal. It's almost never in between, and they never switch shades.
In practice, although my favorite shades are rosy, I've worn French manicures and red. Sometimes I've even done my fingernails with one color and my toenails something different. (As a matter of fact, I just tried a completely new shade for me on my toenails, though I'm not sure yet if I like it.) I guess this is one way real women are more complex than fictional characters.
In my own stories, I've shown strong women making nail polish color choices that reflect their careers and personalities. A starship captain wears dark blue nail polish to match her uniform; the Japanese head of the ISA (International Spacefaring Association) has black-and-white nails painted with Japanese characters.
Do your female characters wear nail polish? If so, do their color choices reflect or deny the stereotypes?