Ubuintuのtmux上のVimでRailscastsカラースキームを使う

http://www.vim.org/scripts/script.php?script_id=2175
.vimrc

 if $COLORTERM == 'gnome-terminal' 
        set term=gnome-256color 
        colorscheme railscasts 
    else 
        colorscheme default 

http://stackoverflow.com/questions/10158508/lose-vim-colorscheme-in-tmux-mode
.zshrc

alias tmux="TERM=screen-256color-bce tmux"

.tmux.conf

set -g default-terminal "xterm"