The KOH Anti-Aging Base Coat is basically a primer for your nails. Your nails become stained after applying dark (especially red) nail polish - this base coat will create a blank palette on your nails, so your polish will appear even and true to color.
Although this is a base coat polish, I use it as a color polish. Four coats will give you a subtle pink color that is clean and natural. After wearing dark polish on my toes for many years, I had deep yellow stains on my nails and was desperate to get them back to their natural color. I used the KOH Natural, Glossy Nail Buffer Set each time I did a manicure to gently remove the top layer of stained nail and applied the KOH Anti-Aging Base Coat. The KOH Anti-Aging Base Coat masked the yellow stains and my toes looked great. Even though my nails are back to their natural color, I still wear the KOH Anti-Aging Base Coat. I love the light pink color and natural nail polish goes with anything.