我正试图在vim下的OSX上使用zenburn。但是，每当我在屏幕下使用vim时，背景都是黑色而不是灰色。我需要在屏幕上设置颜色设置吗？
这是我的screenrc：
vbell off
vbell_msg "Ring"
# detach on hangup
autodetach on
# don't display copyright page
startup_message off
# scroll back
defscrollback 10000
# setup the caption
hardstatus alwayslastline "%{-b gk}%-w%{+b kg}%50>%n %t%{-b gk}%+w %=%C%<"
# right/left bindings
bindkey "^[[c" next
bindkey "^[[d" prev
bindkey "^[[b" focus
# screen 256 color support
attrcolor b ".I"
termcapinfo xterm 'Co#256:AB=\E[48;5;%dm:AF=\E[38;5;%dm'
defbce "on"
# Make terminal scrolling work properly with screen
termcapinfo xterm-256color|xterm-color|xterm|xterms|xs|rxvt ti@:te@
shell -${SHELL}