gmt2rgb(1gmt) on Linux
The text 4db23dfb0952, as Debian 4.0 (Etch) shipped it.
Converting a grdfile, a raw, or a Sun rasterfile to r/g/b grids
Flags it lists
-
-C -
-F -
-G -
-I -
-L -
-R -
-V -
-W