The course explains how to mix colours and adjust them to get as close as you can to your client's skin tone before you tattoo their scars or stretch marks.
Many training courses such as Rodolpho Torres do not explain how to match skin tone properly with limited colours.
If you don't feel confident in how to match skin tone colours, then this is the course for you.
You will be given 4 different colour mixing recipe charts which you can make to help you match client's skin tones more accurately.
Ink brands include World Famous, Eternal, Permablend and the Brazilian / USA inks such is Ironworks.
See https://www.ink-illusion.com/ for more info.