Customizing tmux

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:

run-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
tmux source-file ~/.tmux.conf
  • Or you can add a key binding for it
bind r source-file ~/.tmux.conf \; display "Reloaded ~/.tmux.conf"
  • Or you can quit tmux and start it again
# kill all sessions
<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


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


  • 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.
# Multiple ways of defining style
# --------------------------------

# 1. Define background `bg` and foreground `fg` separately
set-window-option -g window-status-current-fg white
set-window-option -g window-status-current-bg default
# 2. One-liner
set -g pane-border-style 'fg=#585858, bg=#262626'

# 3. Use color variables (double quotes "" are important to get the values)
set -g status-style "fg=${CLOUDS}, bg=${TURQUOISE}"
# Examples with colors AND attributes
  • 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.
# Color Variables

# Inactive Pane
set -g window-style "fg=${WINDOW_FG}, bg=${WINDOW_BG}"

# Active Pane
set -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
select-pane -t:.1 -P 'bg=red'


  • 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:

%if #{==:#{host},myhost} 
set -g status-style bg=red 
%elif #{==:#{host},myotherhost} 
set -g status-style bg=green 
set -g status-style bg=blue 

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 #( )