Finding Your Undertone: Take a close look at the veins on the underside of your wrist. Are your veins blue or purple? If so, then you are cool, and will look good in MakeSense® shades with pink or red undertones. Are your veins green or olive? If yes, you are warm, and will look great in MakeSense shades with yellow undertones. An alternative way to find your undertone is by taking a picture in both a cool-colored shirt (such as gray), and a warm-colored shirt (such as yellow). Whichever you feel you look the best in is likely your undertone. Can’t tell? Then you are neutral.