Green grey and grey are hard to tell apart when photographed if not side by side.
Aged on left, new on right. A slight darkening can be noticed in the older clay (even if it's sealed). Personally, I find the older clay to smooth out better, so don't fret if you get a package with some oil on the surface.
To show the slight green hue to the clay.
A very red red. Adding a hint of black plasticine will make it a little darker like an apple.
A comparison to show the richness of the orange shade
Black clay with other true black objects with different finishes.