Change around the example .tmux.conf to show some newer features.

example_tmux.conf

@@ -5,10 +5,20 @@
 #
 
 # Some tweaks to the status line
-set -g status-bg green
 set -g status-right "%H:%M"
 set -g window-status-current-attr "underscore"
 
+# If running inside tmux ($TMUX is set), then change the status line to red
+%if #{TMUX}
+set -g status-bg red
+%endif
+
+# Enable RGB colour if running in xterm(1)
+set-option -sa terminal-overrides ",xterm*:Tc"
+
+# Change the default $TERM to tmux-256color
+set -g default-terminal "tmux-256color"
+
 # No bells at all
 set -g bell-action none
 
@@ -18,9 +28,6 @@ set -g lock-after-time 1800
 # Keep windows around after they exit
 set -g remain-on-exit on
 
-# Turn on xterm-keys so that additional function keys get escape sequences
-set -g xterm-keys on
-
 # Change the prefix key to C-a
 set -g prefix C-a
 unbind C-b
@@ -49,11 +56,8 @@ bind F12 selectw -t:21
 bind m set monitor-activity
 bind y set synchronize-panes\; display 'synchronize-panes #{?synchronize-panes,on,off}'
 
-# Keys to hide and show a window name from the status line
-bind '-' set window-status-format '#I'\; set window-status-current-format '#I'
-bind '+' set window-status-format '#I:#W#F'\; set window-status-current-format '#I:#W#F'
-
-# Create a single default session
+# Create a single default session, because a session is created here, tmux
+# should be started with "tmux attach" rather than "tmux new"
 new -d -s0 -nirssi 'exec irssi'
 set -t0:0 monitor-activity on
 set  -t0:0 aggressive-resize on