Basic color (underpainting layer) should be applied in multiple semi-transparent layers. Each successive layer should be applied to the previously completely dried layer.
We use a flat brush. Steps should be applied to each other, making sure that moves do not exceed through another moves or through the edge of the area that we paint. In this way, applying more semi-transparent layers, we get completely uniformly colored surface. Usually it is enough to apply 4-5 layers, depending on the degree of color transparency. It is also important that color, after applying the last layer, should be slightly transparent that you can see the drawing below the color layers.
The basic body color is brown or gray-olive (as in this case), or may be in a tone between these two colors. It can be dark or medium brightness, never light (basic color in some way represent a shadow - darker part of the face).