Darkmate for vim is a colorscheme adopted from the gedit text editor.
More details about the theme can be found here.
http://www.yearofmoo.com/2011/04/darkmate.html
The theme can be installed by downloading the theme and placing it into the ~/.vim/colors
folder.
You can also install it with vundle ... just include this into your .vimrc file:
Plugin "yearofmoo/Vim-Darkmate"
Then within your .vimrc
file include this:
colorscheme darkmate