I know this (Witty Gritty) is a beginner video, but I was confused by the skin tones vid. Glennis uses only 3 colours, yellow ochre, alizarin crimson, and cerulean blue. She simply mixes those three up, in various proportions and various strengths and manages to get pale caucasian, afro-caribbean, and olive type skin tones. Just seems simpler to remember those three for everything.