pnmremap(1) on Linux
The text 3e02d3ccb745, as Debian 13 (Trixie), Debian 12 (Bookworm) shipped it.
replace colors in a PNM image with colors from another set
Flags it lists
-
-firstisdefault -
-floyd -
-fs -
-mapfile -
-missingcolor -
-nofloyd -
-nofs -
-norandom -
-randomseed -
-verbose