Have you ever wondered why you can't get your foundation right? Have you been running to the store multiple times buying new shades "GUESSING" they are close enough? Still you waste so much time and money and maybe find the right shade, maybe not. The same with contour and concealer? Well that's what getting a custom color match is about getting you the right shades and correction shades to conceal. The analysis of your skin entails finding your undertone, which a person is either warm, cool, or neutral. Skin tone is also considered in addition as you may be very fair to very dark skin. Why do the undertone & skintone matter? I you have a warm undertone for example and you put on a cool toned foundation it will look patchy, inability to blend well, and just washes you out. Lastly, correction of skin conditions on the face traditionally thought to be fixed with a lighter color. This is where things get interesting, if you are looking to conceal/correct areas of the face you need to neutralize the color of the area with going darker or using a neutralizing color. Putting a lighter concealer over a dark or reddened area is just screaming "LOOK AT ME" because it actually does not hide it. Please look to section on Undertone, Skin Tone, & Color Correction for a more information on how this is all analyzed in depth.