BarnOwl has built-in support for 256color terminals, assuming your libncursesw (and GNU `screen`, if you're using it) support it.

If you're running BarnOwl out of the locker and want 256color support, use `barnowl-256color` instead of `barnowl`.

As of Debian Lenny, the stock screen is built with 256color support, but it is disabled by default.
To enable it, add the following to your `~/.screenrc`.
{{{
# tell screen how to set colors. AB = background, AF=foreground
termcapinfo xterm 'Co#256:AB=\E[48;5;%dm:AF=\E[38;5;%dm'
# erase background with current bg color
defbce "on"
}}}

For older platforms, the barnowl locker has a newer `screen` under the name of `screen-256color`, and /mit/barnowl/etc/screenrc has the aforementioned additions.