The shells are really starting to take shape now and the shadows underneath have been painted in to allow me to better judge my dark and lights. I will likely do another layer for the shadows at least near the shells but this gives me a good idea of the darkest darks.
I used a mixture of Winsor Red & Winsor Green for the shadow which gives a really nice velvety dark. The pigments separate a bit which adds texture as well which is nice.
The shells have been painted using many layers of burnt sienna, indian red, french ultramarine blue and sepia in various combinations.