Slight modification of the default vim colorscheme for better readability (especially when diffing).
Here's what the new diffview looks like:
In comparison to this:
Copy defaultPlus.vim to ~/.vim/colors/ (*nix) or $HOME/vimfiles/colors/ (Windows)
Add colorscheme defaultPlus to your vimrc file (~/.vimrc on *nix, or $HOME/_vimrc on Windows)
Restart vim