@Richard_P I actually use a lot of different colors. Mark's palette, Zorn's palette, my muted palette and various other assortments. What I will do in future is to go for split primary as it broadens the horizon.
Let's paint something modern...things from our world presented in an interesting creative way (I am not suggesting modern art here; only realism). It can be a still life competition consisting of modern objects only. Why not test the limits of creativity here as well - using theory, different lighting, feelings for unusual objects and other crazy ideas?
@PaulB I support Paul's suggestion about modern things but not sure if a lot of us can emulate the style of Sargent. Maybe we can just paint in our own respective styles? Those who can paint like Sargent, they can be extra creative with the subject matter (by making the subject more difficult to paint).