tmux config that looks similar to the default gnu screen

.tmux.conf

# https://github.com/seebi/tmux-colors-solarized/blob/master/tmuxcolors-256.conf
#set-option -g status-style bg=colour235,fg=colour136,default # bg=base02, fg=yellow

# zsh as default shell
set-option -g default-shell /bin/zsh

# set window split
bind-key v split-window -h
bind-key b split-window

# default window title colors
set-window-option -g window-status-style fg=colour237,bg=white # fg=base0

# active window title colors
set-window-option -g window-status-current-style fg=colour255,bg=colour31 # fg=orange

# pane border
set-option -g pane-border-style fg=colour235 #fg=base02
set-option -g pane-active-border-style fg=colour240 #fg=base01

# message text
set-option -g message-style bg=colour235,fg=colour151 # bg=base02, fg=orange

# pane number display
set-option -g display-panes-active-colour colour33 #blue
set-option -g display-panes-colour colour166 #orange
# clock
set-window-option -g clock-mode-colour green #green

set -g status-bg white
set -g status-interval 1
#set -g status-justify centre # center align window list
#set -g status-left-length 20
set -g status-right-length 0
#set -g status-left '#[fg=green]#H #[fg=black]• #[fg=green,bright]#(uname -r | cut -c 1-6)#[default]'
set -g status-left '#[fg=green,bg=blue]'
#set -g status-right '#[fg=green,bg=default,bright]#(tmux-mem-cpu-load) #[fg=red,dim,bg=default]#(uptime | cut -f 4-5 -d " " | cut -f 1 -d ",") #[fg=white,bg=default]%a %l:%M:%S %p#[default] #[fg=blue]%Y-%m-%d'
#set -g status-right '#[fg=blue]%Y-%m-%d'
set -g status-right ''

# C-b is not acceptable -- Vim uses it
set-option -g prefix C-a
bind-key C-a last-window

# Start numbering at 1
set -g base-index 0

# Allows for faster key repetition
set -s escape-time 0

# Rather than constraining window size to the maximum size of any client 
# connected to the *session*, constrain window size to the maximum size of any 
# client connected to *that window*. Much more reasonable.
setw -g aggressive-resize on

# Allows us to use C-a a <command> to send commands to a TMUX session inside 
# another TMUX session
bind-key a send-prefix

# Activity monitoring
setw -g monitor-activity on
set -g visual-activity off

# hjkl pane traversal
bind h select-pane -L
bind j select-pane -D
bind k select-pane -U
bind l select-pane -R

# set to main-horizontal, 66% height for main pane
bind m run-shell "~/.tmux/scripts/resize-adaptable.sh -l main-horizontal -p 66"
# Same thing for verical layouts
bind M run-shell "~/.tmux/scripts/resize-adaptable.sh -l main-vertical -p 50"

bind-key C command-prompt -p "Name of new window: " "new-window -n '%%'"

# reload config
bind r source-file ~/.tmux.conf \; display-message "Config reloaded..."

# auto window rename
set-window-option -g automatic-rename

# https://github.com/edkolev/dots/blob/master/tmux.conf
# Updates for tmux 1.9's current pane splitting paths.

# from powerline
run-shell "tmux set-environment -g TMUX_VERSION_MAJOR $(tmux -V | cut -d' ' -f2 | cut -d'.' -f1 | sed 's/[^0-9]*//g')"
run-shell "tmux set-environment -g TMUX_VERSION_MINOR $(tmux -V | cut -d' ' -f2 | cut -d'.' -f2 | sed 's/[^0-9]*//g')"

# Vi copypaste mode
set-window-option -g mode-keys vi
if-shell "test '\( #{$TMUX_VERSION_MAJOR} -eq 2 -a #{$TMUX_VERSION_MINOR} -ge 4 \)'" 'bind-key -Tcopy-mode-vi v send -X begin-selection; bind-key -Tcopy-mode-vi y send -X copy-selection-and-cancel'
if-shell '\( #{$TMUX_VERSION_MAJOR} -eq 2 -a #{$TMUX_VERSION_MINOR} -lt 4\) -o #{$TMUX_VERSION_MAJOR} -le 1' 'bind-key -t vi-copy v begin-selection; bind-key -t vi-copy y copy-selection'

# status bar
if-shell '\( #{$TMUX_VERSION_MAJOR} -eq 2 -a #{$TMUX_VERSION_MINOR} -lt 2\) -o #{$TMUX_VERSION_MAJOR} -le 1' 'set-option -g status-utf8 on'

# rm mouse mode fail
if-shell '\( #{$TMUX_VERSION_MAJOR} -eq 2 -a #{$TMUX_VERSION_MINOR} -ge 1\)' 'set -g mouse off'
if-shell '\( #{$TMUX_VERSION_MAJOR} -eq 2 -a #{$TMUX_VERSION_MINOR} -lt 1\) -o #{$TMUX_VERSION_MAJOR} -le 1' 'set -g mode-mouse off'

# fix pane_current_path on new window and splits
if-shell "test '#{$TMUX_VERSION_MAJOR} -gt 1 -o \( #{$TMUX_VERSION_MAJOR} -eq 1 -a #{$TMUX_VERSION_MINOR} -ge 8 \)'" 'unbind c; bind c new-window -c "#{pane_current_path}"'
if-shell "test '#{$TMUX_VERSION_MAJOR} -gt 1 -o \( #{$TMUX_VERSION_MAJOR} -eq 1 -a #{$TMUX_VERSION_MINOR} -ge 8 \)'" "unbind '\"'; bind '\"' split-window -v -c '#{pane_current_path}'"
if-shell "test '#{$TMUX_VERSION_MAJOR} -gt 1 -o \( #{$TMUX_VERSION_MAJOR} -eq 1 -a #{$TMUX_VERSION_MINOR} -ge 8 \)'" 'unbind v; bind v split-window -h -c "#{pane_current_path}"'
#if-shell "test '#{$TMUX_VERSION_MAJOR} -gt 1 -o \( #{$TMUX_VERSION_MAJOR} -eq 1 -a #{$TMUX_VERSION_MINOR} -ge 8 \)'" 'unbind %; bind % split-window -h -c "#{pane_current_path}"'


# Colors
# How to use true colors in vim under tmux? #1246 for 2.6 and higher
# https://github.com/tmux/tmux/issues/1246:
# set -g default-terminal "tmux-256color"
# set -ga terminal-overrides ",*256col*:Tc"
# 2.5 and lower:
# set -g default-terminal "screen-256color"

# Doesn't work on iterm2 / mac
# if-shell "test '\( #{$TMUX_VERSION_MAJOR} -eq 2 -a #{$TMUX_VERSION_MINOR} -ge 6 \)'" 'set -g default-terminal "tmux-256color"'
# if-shell "test '\( #{$TMUX_VERSION_MAJOR} -eq 2 -a #{$TMUX_VERSION_MINOR} -ge 6 \)'" 'set -ga terminal-overrides ",*256col*:Tc"'

# Try screen256-color (https://github.com/tmux/tmux/issues/622):
#if-shell "test '\( #{$TMUX_VERSION_MAJOR} -eq 2 -a #{$TMUX_VERSION_MINOR} -ge 6 \)'" 'set -g default-terminal "screen-256color"'
#if-shell "test '\( #{$TMUX_VERSION_MAJOR} -eq 2 -a #{$TMUX_VERSION_MINOR} -ge 6 \)'" 'set -ga terminal-overrides ",screen-256color:Tc"'

#if-shell '\( #{$TMUX_VERSION_MAJOR} -eq 2 -a #{$TMUX_VERSION_MINOR} -lt 6\) -o #{$TMUX_VERSION_MAJOR} -le 1' 'set -g default-terminal "screen-256color"'

set -g default-terminal "tmux-256color"
# Change xterm-256color to the value of TERM before tmux is started
set-option -sa terminal-overrides ',xterm-256color:RGB'
# For older tmux, use this INSTEAD:
#set-option -ga terminal-overrides ',xterm-256color:Tc'
bind-key C-x setw synchronize-panes

# Smart pane switching with awareness of Vim splits.
# See: https://github.com/christoomey/vim-tmux-navigator
is_vim="ps -o state= -o comm= -t '#{pane_tty}' \
    | grep -iqE '^[^TXZ ]+ +(\\S+\\/)?g?(view|n?vim?x?)(diff)?$'"
bind-key -n 'C-h' if-shell "$is_vim" 'send-keys C-h'  'select-pane -L'
bind-key -n 'C-j' if-shell "$is_vim" 'send-keys C-j'  'select-pane -D'
bind-key -n 'C-k' if-shell "$is_vim" 'send-keys C-k'  'select-pane -U'
bind-key -n 'C-l' if-shell "$is_vim" 'send-keys C-l'  'select-pane -R'
tmux_version='$(tmux -V | sed -En "s/^tmux ([0-9]+(.[0-9]+)?).*/\1/p")'
if-shell -b '[ "$(echo "$tmux_version < 3.0" | bc)" = 1 ]' \
    "bind-key -n 'C-\\' if-shell \"$is_vim\" 'send-keys C-\\'  'select-pane -l'"
if-shell -b '[ "$(echo "$tmux_version >= 3.0" | bc)" = 1 ]' \
    "bind-key -n 'C-\\' if-shell \"$is_vim\" 'send-keys C-\\\\'  'select-pane -l'"

bind-key -T copy-mode-vi 'C-h' select-pane -L
bind-key -T copy-mode-vi 'C-j' select-pane -D
bind-key -T copy-mode-vi 'C-k' select-pane -U
bind-key -T copy-mode-vi 'C-l' select-pane -R
bind-key -T copy-mode-vi 'C-\' select-pane -l