In the past at the time with cathode TV ( not far away ) the way peoples saw skin tones was far different
Your TV was Japanese ( tubes mades by Sony ), green was dominant, dead bodies walking
Your TV was European ( tubes made by Philips ), red was dominant, vivid living
Now the LED backlighting technology is almost the same everyhere, but the way you balance your colours, luminosity, correction of this or that is different in almost every home, thus the perception of colours is not the same . What please you as result is conditioned by what you see every day on your screen. It's not purely academic like before the 70ies ( by the way colours pictures film had also those dominants green ( Fuji) red ( Kodak )
Then what are you painting 54mm ? Than basic flesh colours with shadows and highlights is enough . It's when painting far biger size, that you fall in the war of acrylics versus oils, whit a touch of green because, or blue because, of vermillon because, or whatever, there is always a purely academic because, BUT remember, you are painting in 3D not on a flat panel . Lot of peoples came with blah blah this and blah blah that and the theory of colours, and the opposites ( this work perfectly for modern art like Warhool, Picasso, Marvel
... ) But when an uniform is described as deep blue with red facing, don't come with the perfect opposite of blue is ... who cares, the uniform is deep blue with red facing . Or paint a bust sky blue with clouds across the face and call it " This is not a bust ", or paint drawers here and there, or paint it with a painting knife, with very thick medium, or put it in a turning drum and pour some colours on it ... there you can speak about colours theory, and balance, and bla blah blah
Try something simple first ... paint it flesh tone in enamels, let it dry, then put a mix of flesh tone mixed with Sienna ( oils ), wippe it with a sponge lateraly and you got your highlights and shadows, then begin to add more light here, more shadow there, add red to firts mix of oils for the lips, light them up with a bit white then again ( smaller surface ) look at it at 1 foot distance, without magnifying glass and ask you what can I do for even a better result . An do not forgot : " the best is the enemy of the good "
Go have a try . It is practice makes perfect . Best