Your undertone—the subtle hue beneath your skin's surface—determines which makeup shades will look harmonious rather than harsh. Unlike your skin's surface color, which can change with sun exposure or products, undertone stays constant. To find your perfect match, look at the veins on your wrist, consider how your skin reacts to the sun, and test jewelry against your complexion. If you have warm undertones (yellow or golden), cool undertones (pink or blue), or neutral undertones (a balance of both), choosing shades that align with your undertone ensures your makeup enhances your natural beauty instead of fighting it. Start with a simple test, then apply the guidelines below to foundations, concealers, blushes, lipsticks, and eyeshadows for a seamlessly radiant look.…