How does the tmux color palette work?

Question

I'm trying to set something to gray, but can't figure out how. The only bit of info in the man page about colors I can find is:

message-bg colour
  Set status line message background colour, where colour is one of:
  black, red, green, yellow, blue, magenta, cyan, white, colour0 to
  colour255 from the 256-colour palette, or default.

I also found a blog post which iterates through colors, but I can't quite grok it, and don't want to sit at the terminal all day guessing color numbers until one works.

Answer 1

You can get a list with this bash snippet:

for i in {0..255}; do
    printf '\x1b[38;5;%dmcolour%d\x1b[0m\n' $i $i
done

Then use colourxxx with tmux.

Answer 2

I found this image to be enlightening.

Answer 3

In Subversion (what will be tmux 1.5) you can also use #abcdef hex-style colours which are mapped to the nearest 256 colour palette entry. You need quotes as it's treated as a string, whereas regular color names are treated as named constants. Also note that 3-letter shorthand (#f00) is invalid.

Example:

set pane-active-border-bg red # no quotes for name
set pane-active-border-bg "#ff0000" # quotes for rgb

Answer 4

Before tmux 3.2 (released in April 2021), tmux only supported the international (British) spelling for the 256 colour palette, e.g.

"colour121"

as opposed to the American spelling that drops the u

"color121"

If you're using tmux 3.2 or later, you can spell it either way.

Answer 5

I've been using the xterm-color-table.vim script. Any 256 color terminal color table will work.

Answer 6

Building up on @cYrus' answer, I wrote a script to break the output of the colors into N number of columns, where N is the first argument

# colors.sh

#!/bin/bash
if [ -z $1 ]; then
    BREAK=4
else
    BREAK=$1
fi
for i in {0..255} ; do
    printf "\x1b[38;5;${i}mcolour${i} \t"
    if [ $(( i % $BREAK )) -eq $(($BREAK-1)) ] ; then
        printf "\n"
    fi
done

Try it by saving it into a file called colors.sh, then ./colors.sh 4

Don't forget to chmod +x colors.sh first.

Answer 7

I find this function producing the most concise and clear output (it's not mine):

colors () {
    for i in {0..255}
    do
        print -Pn "%K{$i}  %k%F{$i}${(l:3::0:)i}%f " ${${(M)$((i%6)):#3}:+$'\n'}
    done
}

Then you use colourXXX where XXX is the three digits code printed above as the value for fg=, bg= etc...