I'm unhappy with the default syntax highlighting in vim and would like to change it. I tried to follow the accepted answer on this page, but I think my vim version (7.4) is different.

Inside /usr/share/vim/vim74/syntax I have tons of files, so I decided to edit php.vim. But I find that the format in the file isn't like the one in the link I mentioned. Here's my php.vim file.

Can someone help me figure out how to customize vi syntax highlighting?