Base: Olive Green + French Blue + Prussian Blue
Shadows: Base + Prussian Blue + Burnt Umber
Highlights: Base + Skin Tone Base
The key is to paint in thin layers and create a gradual transition of colors that is lightest at the top (shoulder) to the lowest part of the bust. To emphasise the highlights, a mix of Skin Base Tone + White was used to pick out the highest areas. Likewise to create a distinct shadow area, a mix of Prussian Blue + Burnt Umber was introduced into the darkest folds of the uniform. In some case, I used Carbon Black to further vary the dark areas.
A fellow member of planetFigure (Thanks Nap !) introduced me to a product, Kristal Klear, to create the lenses of the glasses. I found a youtube video (https://www.youtube.com/watch?v=SZ_ggnLYkPM) showing how it was done. In the case of this bust, I used a size 2 brush instead of a toothpick to drag the medium across the glasses as the gap is larger.