Studio Radiance Face and Body Radiant Sheer Foundation is an ultra-light, waterproof foundation that provides a sheer buildable veil of coverage with a natural, radiant glow. This iconic foundation reveals your skin with a sheer, radiant finish for a my skin but better effect. The formula provides refreshing, instant hydration in an ultra-light, waterproof formula with all-day comfort and wear. It is long-wearing up to 8 hours, provides stay-true color for 8 hours, is waterproof, instantly hydrating, does not cause acne, and is suitable for all skin types including sensitive skin. It is dermatologist-tested and ophthalmologist-tested. Choosing the right foundation shade: Each shade is identified by a letter and a number. The Number indicates how dark the shade is; higher numbers mean darker shades. Fair complexions are between 4 and 20. Medium skin tones are between 20 and 40. Darker complexions are between 40 and 54. The Letter represents the undertone: C equals Cold, NC equals Neutral and Cold, N equals Neutral, NW equals Neutral and Warm, W equals Warm. If your veins are green, your undertones are warm. If veins are mostly blue or purplish, you have cold undertones. If you have both, your undertones are neutral.