After researching and finding tutorials on how to edit Dreamweaver configuration files and none working exactly I finally thought of a solution.
In the comments in the beginning of the php file that I want to be rendered as css put an html style tag like this:
/*
<style>
Style Sheets
....
Copyright © 2012 All Rights Reserved
*/
@charset "utf-8";
#myID {
background:<?php echo $colorVar; ?>;
}
This works perfectly. It enables syntax highlighting and code hinting as if the rest of the file were css and still has correct php syntax highlighting for <?php ?>
tags.
Hope this helps someone else along the way.