Customizing tmux

How to create a tmux theme, load changes and define styles and formats for the panes and status bar

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Aug 17, 2018
Last updated: Aug 19, 2018
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3 minutes

Finished theme: tmux Flat Theme

tmux Flat Theme

There are example templates available in the /usr/share/doc/tmux/examples folder which are a really good starting point and help you understand how to configure your own theme

creating a tmux theme

You can edit the ~/.tmux.conf file directly and add your styles or you can save the theme separately and load it from the conf file.

Add this line to the bottom of ~/.tmux.conf:

1run-shell ~/file/path/flatui-theme.tmux

This approch is safer as you are not editing your conf file directly and won’t mess it up by chance. It is also good when you’re testing multiple themes. You can just comment/uncomment the line that loads a theme instead of overwriting the entire .tmux.conf file every time

reloading the changes

You can either load the file from inside tmux
You can load the file from the Terinal

1tmux source-file ~/.tmux.conf

Or you can add a key binding for it

1bind r source-file ~/.tmux.conf \; display "Reloaded ~/.tmux.conf"

Or you can quit tmux and start it again

1# kill all sessions
2<prefix> &

In cases when you can’t see your changes but are sure you made them, try quitting and restarting tmux and see if it is giving any errors

Panes

-g shows the styles for the current pane -T sets the title for the current pane

Customization

You can save color variables like Bash HIGHLIGHT="#3fcfff" and use the $HIGHLIGHT
You can use terminal colors (black, red, green, yellow, blue, magenta, cyan, white etc.), Hexadecimal (’#ffffff’, all 6 digits, no #FFF shorthand, needs to be in commas), and 256 colour set: (colour0 till colour256)
Possible color values:
- Hexadecimal ('#ffffff', all 6 digits, no #FFF shorthand, needs to be in commas)
- Terminal colors (black, red, green, yellow, blue, magenta, cyan, white)
- 256 colour set: colour0 till colour256
You can use the default keyword to use default colors.
Possible Attribute values:
- none, bright, bold, dim, underscore, blink, reverse (reverses the FG and BG colors), hidden, italics, strikethrough (bold, underscore and reverse worked for me)
- to disable the attribute, prefix with no. e.g. noreverse, noitalics etc.

 1# Multiple ways of defining style
 2# --------------------------------
 3
 4# 1. Define background `bg` and foreground `fg` separately
 5set-window-option -g window-status-current-fg white
 6set-window-option -g window-status-current-bg default
 7
 8# 2. One-liner
 9set -g pane-border-style 'fg=#585858, bg=#262626'
10
11# 3. Use color variables (double quotes "" are important to get the values)
12set -g status-style "fg=${CLOUDS}, bg=${TURQUOISE}"

1# Examples with colors AND attributes
2fg=yellow,bold,underscore,blink
3bg=black,fg=default,noreverse

Variable substitution only works if you use double commas " "

Pane Styles

by default window-style and window-active-style are used to style a pane.

 1# Color Variables
 2WINDOW_FG="#95a5a6"
 3WINDOW_BG="black"
 4WINDOW_ACTIVE_FG="#ecf0f1"
 5WINDOW_ACTIVE_BG="black"
 6
 7# Inactive Pane
 8set -g window-style "fg=${WINDOW_FG}, bg=${WINDOW_BG}"
 9
10# Active Pane
11set -g window-active-style "fg=${WINDOW_ACTIVE_FG}, bg=${WINDOW_ACTIVE_BG}"

you can also set the style for a single pane by using the select-pane option with the -P flag

1select-pane -t:.1 -P 'bg=red'

Conditionals

You can use conditionals in config files

Within a configuration file, commands may be made conditional by surrounding them with %if and %endif lines. Additional %elif and %else lines may also be used. The argument to %if and %elif is expanded as a format and if it evaluates to false (zero or empty), subsequent lines are ignored until the next %elif, %else or %endif. For example:

1%if #{==:#{host},myhost}
2set -g status-style bg=red
3%elif #{==:#{host},myotherhost}
4set -g status-style bg=green
5%else
6set -g status-style bg=blue
7%endif

Will change the status line to red if running on ‘myhost’, green if running on ‘myotherhost’, or blue if running on another host.

Existing variables and running commands

Special character sequences are enclosed in #{ }
Commands are enclosed in #( )

#(pwd)
#{pane_current_path}

Links

tmux Manual

Notes