correct tmux theme script and update colors

* update colors and correct variable usage in tmux theme file
* update colors in battery indicator script

bin/battery_indicator.sh

@@ -17,10 +17,10 @@ if [[ $charged_slots -gt 3 ]]; then
   charged_slots=3
 fi
 
-echo -n '#[fg=red]'
+echo -n '#[fg=colour196]'
 for i in `seq 1 $charged_slots`; do echo -n "$HEART"; done
 
 if [[ $charged_slots -lt 3 ]]; then
-  echo -n '#[fg=white]'
+  echo -n '#[fg=colour254]'
   for i in `seq 1 $(echo "3-$charged_slots" | bc)`; do echo -n "$HEART"; done
 fi