Learn How to Mix Skin Colors

Below is my Skin Color Palette which I have given out at some of my classes.  My students have found it very helpful. 

For Asian and Caucasian baby skin, add a tiny bit of yellow to the lightest value of the top row.
For black skin, use any of the darker and medium colors, with some interesting shadows created using sap green with a little white.  Light hilights use cool colors as in the lightest values in the 5th and 6th rows. American Indians call for a little more reddish in the skin, with dark shadows.

A Note About Painting Portraits ~

Unlike painting a landscape, you must have a good photograph of your subject.  Preferably in good lighting, large format photo, clear and crisp, printed on gloss photo paper.  The more information you have about your subject (by information I mean detailed, clearly seen photo) the easier it is to get a likeness.  I do not recommend changing any part of the position from what your photograph is.  The best way to paint a portrait is using a model, where you will find limitless opportunities to see all aspects of the face.

It is not always possible to get a clear photograph, especially if the subject is someone who has passed on.  In that case, get all the photographs you can of the subject, color and black and white, and pick the best pose and paint it using all the extraneous information on the photographs you have collected.