Doug Miller notes:
the sapwood is indeed white, or nearly so, when it's fresh, and it
*does* darken over time. But to say that it becomes "almost as dark as
the
heartwood" is a bit of an exaggeration. I have a cherry bookcase built
almost
18 years ago on which the sapwood on the sides is still clearly
visible.

Yes. And I discovered not too long ago that cherry from different areas
is a different color. Recently, I gave a friend some 10/4 cherry to use
as feet on quilt racks. He built most of the rest out of 4/4
Pennsylvania cherry. The Pennsy cherry was substantially darker than
our Virginia cherry. Both woods were freshly machined. Something to do
with soil content, I guess.