The key is to pick a color that compliments your skin tone. Use the guide below and some of my suggestions in picking a red color that is perfect for you.
Cherry Lips seen on fair, medium and dark skin tones
In order for your lipstick to be flawless, make sure to exfoliate your lips, line your lips with lip pencil, use a brush to apply your lipstick, and blot after applying to seal the color.
For Medium Skin:
MAC Hang Up, Chanel Rouge Allure Luminous Lip Color in Coromandel, NARS