In a very a stereotypical sense, it is not a normal shade, or even close for a yellow color. My reason, the overall color of the model is purple with a yellow contrast. There really isn’t any place in the model for a brown or red-brown without disrupting the “feel” of the figure. She is meant to be mysterious, alien, distant and other-worldly. The purple pushes this feel so I don’t want to clutter it up with introducing too many colors or to take away from the face mask which is one of the central features your eye will be drawn to. On the color wheel green is between blue and yellow. Purple is between blue and red. Both Purple and green, to a lesser extent, are cool colors. So to keep the theme or feel predominantly cool and mysterious, I use green to shade the yellow. I followed a standard Non-Metallic Metallic technique with a level of reflection that is not the same as a mirror finish, but is sharp enough to have a Sky and Earth reflection. By sky and earth I will create a reflection of the horizon on my model.
Sky and Earth is also used mostly to reflect the blue sky and brown earth. My metal is a yellow gold, so I used different shades of yellow and green instead of blue and brown.