Fred M. Erickson
Relief painted with the neutral scheme
These gradients were taken from the source-code of drawmap, a cartographic package by Fred M. Erickson. They are a work derived from drawmap and so, like it, are released under the GNU General Public Licence. The original gradients were in feet; in translation I have also made versions in metres, using 300 metre intervals rather than 1000 feet.
From the file colors.h in the drawmap distribution:
There are actually four color tables defined: One very garish one based on the spiral, another more natural one that includes the colors typically associated with the vegetation and rocks at various altitudes, a neutral one that is intended to look natural without being very obtrusive, and one that is reminiscent of maps in school textbooks and is sort of midway between the spiral and the natural.
Copyright is GPLv2: See details and XML record.