Once you know your undertone, narrow your choices to three shades that appear closest to your jawline. Never test foundation on your arm, as that skin is often darker or more freckled than your face. Swipe the three shades in parallel lines from your lower cheek down to your neck. The correct shade is the one that "disappears" into both your face and neck. This ensures you won't have a visible line at your chin.
Lighting is the final, most crucial factor. Artificial department store lights are notorious for distorting colors. After applying your test swatches, walk to a window or step outside with a hand mirror. Check the color in natural daylight; this is the only environment that reveals the truth. Additionally, give the formula about ten minutes to "settle." Some foundations oxidize, meaning they react with the air or your skin's oils and turn slightly darker or more orange over time. how to buy foundation color
Buying the perfect foundation requires a blend of science, lighting, and patience. Most people make the mistake of testing shades on their wrists or under harsh store lights, leading to a mismatched "mask" effect. To find your true second skin, you must evaluate your skin from the inside out. Once you know your undertone, narrow your choices