I returned to working on this portrait today.
I added some darker values. On the clothing, I applied a thin earth green wash, then used a smaller brush to put in more concentrated green accents. I worked these green values into the rest of the figure. I think it needs a bit more work to balance out the values.
I tried to de-saturate the background by using unbleached titanium white and deep naples yellow. And I tried to accentuate the face and skin by mixing naples yellow light with patches of orange, pink and yellow.