HTML/OS (by Aestiva)

The coloring scheme for HTML/OS works as follows:

Functions and variable names are the same color by default because VIM doesn't specify different colors for Functions and Identifiers.  To change this (which is recommended if you want function names to be recognizable in a different color) you need to add the following line to either your ~/.vimrc or $VIM/syntax/synload.vim file:
> hi Function term=underline cterm=bold ctermfg=LightGray

Of course, the cterfg can be a different color if you choose.

Another issues that HTML/OS runs into is that there is no special filetype to signify that it is a file with HTML/OS coding.  You can change this by adding or modifying a line in $VIM/filetype.vim, or by opening a file and turning on HTML/OS syntax by doing the following
> :set syntax=htmlos

Lastly, it should be noted that the opening and closing characters to begin a block of HTML/OS code can either be << or [[ and >> or ]], respectively.