Wikipedia says on the behalf of the nailpolish, that "[n]ail polih is a lacquer that can be applied to the human fingers or toe nails to decorate and protect the nail plate. The formulation has been revised repeatedly to enhance its decorative effects and to suppress cracking or flaking."
It is said that the first nail decorators were the Indians who used henna to adorn their nails. In ancient China painting nails was only a priviledge of royalty. The first women to be known for painting their nails red were Egyptians, Nefertiti and later Cleopatra. Nefertiti, one of the most famous beauties of the ages past, is alleged to use henna and even blood to paint her nails. The red colour of was also reserved only for royalty.
At the beginning of the 9th century, nails were adorned with red scented oils. In the 19th century powders were used to decorate one´s nails, but in 1920s something more permanent was used as a nail paint, car paints. Michelle Manard, French make-up artist, came with the idea to adapt the car paint to a nail polish. In 1917 Cutex created the first nail polish and in the early 1930s nailpolishes by the Charles Revson Company / Revlon company were introduced. The first manicure style where the red nailpolish was used was the halfmoon manicure which leaves the moon and the tip of the nails unpainted.
A huge turn was made when Technicolor was invented, because the movies were now in colours, the viewers could admire the looks of the actresses and copycat their style. The actress Rita Hayworth was a pioneer of the red nails and lips on the silver screen. The demand for the red nail enamels grew immediately. This trend lasted up until the 1960s when the pastel and more natural shades of nailpolishes came into fashion.