How to extract the colours from a PDF

Try this script:

( # Run in a subshell so it won't crash current color settings
    dircolors -b >/dev/null
    IFS=:
    for ls_color in ${LS_COLORS[@]}; do # For all colors
        color=${ls_color##*=}
        ext=${ls_color%%=*}
        echo -en "\E[${color}m${ext}\E[0m " # echo color and extension
    done
    echo
)

Output:

There is some information on 256-color support in the tmux FAQ.

Detecting the number of colors that the terminal supports is unfortunately not straightforward, for historical reasons. See Checking how many colors my terminal emulator supports for an explanation. This means that

• tmux cannot reliably determine whether the terminal supports more than 8 colors;
• tmux cannot reliably communicate to the application that it supports more than 8 colors.

When you're in tmux, the terminal you're interacting with is tmux. It doesn't support all of xterm's control sequences. In particular, it doesn't support the OSC 4 ; … control sequence to query or set color values. You need to use that while directly running in xterm, outside tmux.

If you run tmux -2, then tmux starts with 256-color support, even if it doesn't think that your terminal supports 256 colors (which is pretty common).

By default, tmux advertises itself as screen without 256-color support. You can change the value of TERM in .tmux.conf to indicate 256-color support:

set -g default-terminal "screen-256color"

You can use TERM=xterm-256color or TERM=screen-256color on Ubuntu. These values will only cause trouble if you log in to a remote machine that doesn't have a termcap/terminfo entry for these names. You can copy the entries to your home directory on the remote machine; this works with most modern terminfo implementations.

# From the Ubuntu machine to a machine that doesn't have *-256color terminfo entries
ssh somewhere.example.com mkdir -p .terminfo/s .terminfo/x
scp -p /lib/terminfo/s/screen-256color somewhere.example.com:.terminfo/s/
scp -p /lib/terminfo/x/xterm-256color somewhere.example.com:.terminfo/x/