vim: Change statusline colour based on mode

Here is my vimrc statusline configuration:

" statusline
" format markers:
"   %t File name (tail) of file in the buffer
"   %m Modified flag, text is " [+]"; " [-]" if 'modifiable' is off.
"   %r Readonly flag, text is " [RO]".
"   %y Type of file in the buffer, e.g., " [vim]".
"   %= Separation point between left and right aligned items.
"   %l Line number.
"   %L Number of lines in buffer.
"   %c Column number.
"   %P percentage through buffer
set statusline=%t\ %m%r%y%=(ascii=\%03.3b,hex=\%02.2B)\ (%l/%L,%c)\ (%P)
set laststatus=2
" change highlighting based on mode
if version >= 700
  highlight statusLine cterm=bold ctermfg=black ctermbg=red
  au InsertLeave * highlight StatusLine cterm=bold ctermfg=black ctermbg=red
  au InsertEnter * highlight StatusLine cterm=bold ctermfg=black ctermbg=green
endif

It displays some useful information about the file and your position within it. It also automatically changes the colour of the statusline from red to green when you enter INSERT mode and back to red when you leave it.

This is what the status line looks like in INSERT mode:

Foo.java [RO][java]

(ascii=097,hex=61) (158/667,23) (26%)

To see a description of all possible status line variables type :help statusline in vim.

To see my complete vimrc visit my GitHub dotfiles repository.