Exactly what colors you use for painting skin tones and how many is a matter of personal preference and style. About the only thing that's certain is that having one or two tubes of paint labeled "skin color" isn't going to suffice.
The paint shown in the photo is a tube of "Light Portrait Pink" acrylic, produced by Utrecht. I've had it about 15 years and as you can see, I've used only a smidgen. It's simply too pink for me, and I got better skin tones mixing from scratch than adding to this (it's a mixture of three pigments: naphthol red AS PR188, benzimdazolone orange PO36 and titanium white PW5). So it's lurked in the bottom of my paint box, neglected.
My preferred colors for mixing skin tones are:
- Titanium white (with watercolor, the paper acts as the white)
- Titanium buff
- Cadmium yellow (medium or dark)
- Cadmium red
- Burnt sienna
- Raw umber
- Prussian blue
- Payne's grey (not essential, but useful)
If you don't like using cadmium pigments, substitute whichever red and yellow is your favorite. The advantages of cadmium red and yellow are that they're both warm colors and have very strong tinting strength (so a little goes a long way). It's well worth experimenting with all the red and yellows you have, to see the results you get.
The blue can be whichever you prefer too. I like Prussian blue because it's so dark when it's used thickly, yet very transparent when used thinly.
These are certainly not the only options open to you. Everyone develops their personal preference through time. Experiment with golden ochers, deep purples, ultramarine blue, and greens. Pay attention to the underlying color of your model's skin: is it red, blue, sallow yellow, warm yellow to gold, or pale cream?
Remember: a little of a dark color mixed into a light has a much greater impact than the same quantity of light mixed into a dark.
