Early start on Wayne M. Portrait

I've started laying down some "local" colour in the figure and background, but know I have a long way to go. I'm not sure yet how I'll deal with the bulky window frame or the furniture behind the figure, so I'm setting them aside for now. My goal is to colour in the clothing and body, getting the correct values in the lights and shadows, and the immediate background of the curtain. In fact, I'll know when I'm ready to move on when I have 4 distinct values: the background, the cast shadows inside the figure and on the floor, the contained shadows in the figure (like the neck area) and the areas in direct light... I know appreciate why some old masters worked first in grisaille (monochrome) before adding colour...