This is a semi-colored grisaille underpainting done over a drawing done
with a mechanical pencil and then covered with a thin layer of acrylic
medium tinted orange. The oil colors used to develop the picture so far
where simply black and white, with a bit of brown and green on the mag-
The interesting color phenomenon occurring here is do to a situation
known as "optical grays". That is that any medium (center of a value scale
of five values) gray placed near a color or about the same value and intensity
will take on the complement of that color. Notice how the sphere appears to
be blue in parts. This is because the background is slightly orange. The
sphere is really only a gray made of black and white.
Color is amazing.