Mainly the palette is a mix of two colors of Andreas Model:
Napoleonic red and Napoleonic green
Mixed in different part we can obtain several red tones, from the shadows (more desaturated) to the lights (more vibrant). Once found the volumes, I use as usual, the blending technique, applying the same tones very diluited and creating a sort of filters that give a smooth surface.
At one point I had to retouch the extreme lights and so I added to the Napoleonic red a bit of French orange (only a bit) , just to push further the lights.