Matching your undertone can be a dilemma for dark brown skin tones. Many companies defer to red. But if the base is too red, the foundation leaves an obvious line of demarcation between your jawline and your neck. To find your undertone, take a look at the veins in your forearm. “If they appear blue, then you’re most likely cool,” explains Uzo, Nars international makeup stylist. “If they look more green, then you’re warm.” Technology is making the search easier too: Artistry Balancing Foundation’s ($26, amway.com) Ideal Shade Technology allows the pigment to self-adjust to mimic your exact skin tone.