Toggle light/dark for terminal + vim

.vimrc

let base16colorspace=256
colorscheme base16-default-dark
let shellbg=$SHELLBG
if shellbg == 'dark'
  set background=dark
  highlight LineNr ctermfg=blue ctermbg=black
else
  set background=light
  highlight LineNr ctermfg=blue ctermbg=white
endif

.zshrc

# colors

BASE16_SCHEME="default"
SHELLBG="dark"

darken () {
  export SHELLBG="dark"
  colorize
  PROMPT=$'$FG[240]%~ $FG[255]% ${vcs_info_msg_0_}\n$ '
}

lighten () {
  export SHELLBG="light"
  colorize
  PROMPT=$'$FG[240]%~ $FG[0]% ${vcs_info_msg_0_}\n$ '
}

colorize () {
  SHELL_SCHEME="base16-${BASE16_SCHEME}-${SHELLBG}.sh"
  BASE16_SHELL="$HOME/.terminal/colors/base16-shell/scripts/${SHELL_SCHEME}"
  [[ -s $BASE16_SHELL ]] && source $BASE16_SHELL
}

darken # default to dark colors