Why do fingernails and toenails turn white when they grow longer?

White Nails: Nails are held on to your fingers and toes by suction ( which gives it the pinkish color )....As the nail grows out past the end of the finger or toe, the nails color changes. Nails natural color is whiteish because they are translucent.

Air under the nail: Pink color is the skin under the nail..When they get longer they are not attached look white.