I thought it might be interesting to show the process behind painting this portrait from life. The painting on the left shows the stage where I am thinking about putting down lots of color and finding the planes of the face and features. In the painting on the right, I've taken my trusty Langenickel soft brush and softened everything I did in the first stage, then added a few details like nostrils and highlights to bring it all together.
Here are the colors that I used in the light areas of her face. I begin by mixing Cadmium Yellow Light, Cadmium Scarlet, and Titanium White for a basic warm skin tone. Then I added a drop of green, then Cerulean Blue, then Quinacridone Rose, then more Cadmium Yellow to change the color of the skin ever so slightly.
For the shadows on her face and neck, I started with a mixture of Ultramarine Blue with Quinacridone Rose and Titanium White. To this mixture, I added Cadmium Scarlet, then a medium value green, then Cerulean Blue, and lastly I mixed Yellow Ochre to my basic purple color. This gave me a nice range of shadow colors to play with.
When I softened her face, I tried to let the colors stay separated just a bit. I have a tendency to over blend and lose the color excitement. When I find a good balance, I put my brush down and walk away quickly!