Look at Your Skin
Examine your skin closely in a mirror, in a well-lit room. It would be better to do this in natural light. Try looking for gold/ yellow or pink/blue tones. If your skin has yellow hues, you have a warm undertone. A pinkish hue would mean a cool undertone. If you can’t really tell, then you might have a neutral undertone.
Check Your Wrists
Take a close look at the color of your veins. if your veins appear to be blue or purple, then you have a cool undertone. If your veins look green veins, you are warm-toned. If you cannot decide which color is dominant, you may be neutral.
Wear Some Jewellery
Take your favorite piece of silver and gold jewelry and put it against your skin. If you look better in silver your skin color is cool, and if you look better in gold jewelry, your skin color is warm. If you look equally good in both, you may have neutral undertones.
Examine Your Eyes
If your iris has more blue and green specs in your eyes, your undertone is cool, whereas more brown or gold specks mean your undertone is warm.
It is easy to find the perfect shade for every skin color in every hair color tree. You need to choose a shade from the hair color chart that will neutralize your undertone. So, if you are cool-toned, you need to find the warm-toned shade of your chosen hair color. If you are neutral, you can choose any hair color since both cool-toned and warm-toned shades will look great on you.