COOL OR WARM UNDERTONE
Prior to each treatment, regardless of which technique, it is important to look at the skin type in order to determine the correct color (s). Does your customer have a warm undertone or a cool undertone? A cool undertone is often pink and bluish while a warm undertone tends to yellow or peach. It may also be that your customer has a neutral undertone, or a mix of a cold and warm undertone. Then there is simply no clear undertone to be distinguished. If there is a warm undertone, the pigment that you use can become too red in some cases. That is why you can work better with ash colors in this case. If the semi-permanent make-up decreases over time, the red color will show up more and more.