I have installed vim in Debian 6. I am trying to change color scheme and enable syntax highlighting. But it's not working. I added set background=dark in .vimrc file. But white background is displaying. I wonder what went wrong?

Here is my .vimrc file: http://pastebin.com/8k2gpWDh

I installed robokai colorscheme which has dark background. But the background looks white instead dark. Other colors of colorscheme working.

vim color-scheme vim-syntax-highlighting
Edit
Report