Você pode programar a paleta de cores usando seqüências de escape, ou melhor, usando tput
.
Existe um script nas fontes do xterm que demonstra as sequências de escape:
einvertendoapaletacomoscript:
Issoépara
Você poderia compilar o xterm para suportar 256 recursos de cores, mas perder o UTF-8, como indicado no manual :
Resources past color15 are available as a compile-time option.
Due to a hardcoded limit in the X libraries on the total number
of resources (to 400), the resources for 256-colors are omitted
when wide-character support and luit are enabled. Besides
inconsistent behavior if only part of the resources were
allowed, determining the exact cutoff is difficult, and the X
libraries tend to crash if the number of resources exceeds the
limit. The color palette is still initialized to the same
default values, and can be modified via control sequences.