Now for some technical information regarding technique. I used none other than bristle brushes for this painting to this stage.
OK ... we started with a value 4-5 burnt umber with a blue-gray interior for the figures. The blue gray was molded in the chiaroscuro manner and allowed to settle and dry. A higher value mix of light red/burnt umber and flake white was used to bring the flesh up to a warmth in the secondary areas (or turning point areas)that pointed upwards. The turning point areas that pointed down were left blue-gray(as seen in the background). In certain other areas close to the ground, and reflecting down, a little yellow was added. This took care of most secondary areas.
Working back from the highlights with a flake white, sometimes with a little red added and sometimes with a touch of ultramarine, and using a small bristle (1/4"), cut and blend the highlights into the secondary values. If desired at this stage you can add veins and other secondary areas as well painting wet-in-wet as time permits and adjusting as you wish.
The middle distance is best kept indistinct, yet atmospheric, while the foreground should not detract from the overall design.