title: Load different colorscheme when using vimdiff
body: <p>How to load a different colorscheme when doing <code>vimdiff</code>. </p>
  
  <p>I want this because the my current colorscheme does not show some diffs properly in <code>vimdiff</code>, For. eg some diff is shown with same fg/bg color. This makes it very hard to understand the diff. So every time i do a <code>vimdiff</code> i have to do <code>:colorscheme some_other_scheme</code></p>
  
  <p>Can this be done in <code>.vimrc</code> file?</p>