Wood is a natural product, and as it oxidizes and is exposed to
light, it changes color. Some species—American cherry, Brazilian
cherry and others, especially exotics—are known to change
color drastically. There is no way to prevent this, although
waiting as long as possible (ideally, at least six months) after
the floor is installed to place rugs can help. So can moving area
rugs from time to time. If you already have distinct lines on the
floor, though, there isn’t usually a quick fix to remove them
(even resanding won’t always remove the color difference).
The unexposed part of the floor will eventually “catch up” to
the rest of the floor, if you can live with looking at the floor
as-is until then.
Answered on 5/5/2011 by Tech & Install