.tmux.conf

set -g activity-action other
set -g assume-paste-time 1
set -g base-index 0
set -g bell-action any
# set -g default-command
set -g default-terminal "screen-256color"
set -g default-shell /usr/bin/zsh
set -g default-size 80x24
set -g destroy-unattached off
set -g detach-on-destroy on
set -g display-panes-active-colour red
set -g display-panes-colour blue
set -g display-panes-time 1000
set -g display-time 750
set -g history-limit 2000
set -g key-table root
set -g lock-after-time 0
set -g lock-command "lock -np"
set -g message-command-style fg=yellow,bg=black
set -g message-style fg=black,bg=yellow
set -g mouse off
set -g prefix C-b
set -g prefix2 None
set -g renumber-windows off
set -g repeat-time 500
set -g set-titles off
set -g set-titles-string "#S:#I:#W - \"#T\" #{session_alerts}"
set -g silence-action other
set -g status on
set -g status-bg green
set -g status-fg black
set -g status-format[0] "#[align=left range=left #{status-left-style}]#{T;=/#{status-left-length}:status-left}#[norange default]#[list=on align=#{status-justify}]#[list=left-marker]<#[list=right-marker]>#[list=on]#{W:#[range=window|#{window_index} #{window-status-style}#{?#{&&:#{window_last_flag},#{!=:#{window-status-last-style},default}}, #{window-status-last-style},}#{?#{&&:#{window_bell_flag},#{!=:#{window-status-bell-style},default}}, #{window-status-bell-style},#{?#{&&:#{||:#{window_activity_flag},#{window_silence_flag}},#{!=:#{window-status-activity-style},default}}, #{window-status-activity-style},}}]#{T:window-status-format}#[norange default]#{?window_end_flag,,#{window-status-separator}},#[range=window|#{window_index} list=focus #{?#{!=:#{window-status-current-style},default},#{window-status-current-style},#{window-status-style}}#{?#{&&:#{window_last_flag},#{!=:#{window-status-last-style},default}}, #{window-status-last-style},}#{?#{&&:#{window_bell_flag},#{!=:#{window-status-bell-style},default}}, #{window-status-bell-style},#{?#{&&:#{||:#{window_activity_flag},#{window_silence_flag}},#{!=:#{window-status-activity-style},default}}, #{window-status-activity-style},}}]#{T:window-status-current-format}#[norange list=on default]#{?window_end_flag,,#{window-status-separator}}}#[nolist align=right range=right #{status-right-style}]#{T;=/#{status-right-length}:status-right}#[norange default]"
set -g status-format[1] "#[align=centre]#{P:#{?pane_active,#[reverse],}#{pane_index}[#{pane_width}x#{pane_height}]#[default] }"
set -g status-interval 15
set -g status-justify left
set -g status-keys emacs
set -g status-left "[#S] "
set -g status-left-length 10
set -g status-left-style default
set -g status-position bottom
set -g status-right "#{?window_bigger,[#{window_offset_x}#,#{window_offset_y}] ,}\"#{=21:pane_title}\" %H:%M %d-%b-%y"
set -g status-right-length 40
set -g status-right-style default
set -g status-style fg=black,bg=green
set -g update-environment[0] DISPLAY
set -g update-environment[1] KRB5CCNAME
set -g update-environment[2] SSH_ASKPASS
set -g update-environment[3] SSH_AUTH_SOCK
set -g update-environment[4] SSH_AGENT_PID
set -g update-environment[5] SSH_CONNECTION
set -g update-environment[6] WINDOWID
set -g update-environment[7] XAUTHORITY
set -g visual-activity off
set -g visual-bell off
set -g visual-silence off
set -g word-separators " "

Working tmux configuration (w/ zsh).
Sometimes color on tmux breaks when using zsh + autosuggestions.
Create a config file, then use copy&paste the content.
OR
Run a session, detach it, and then run:
tmux show -g | cat > ~/.tmux.conf
then, comment out default-command, and add set -g default-terminal "screen-256color".