Dynamic colors for node bodies
I haven't done it to make inline CSS, but you could try creating a new region in your .info, and using drupal_set_content to add structured content.  You can then parse / format it in a template_preprocess_page, and then print it in your page.tpl.php.  I've had to resort to similar tricks in the past to work around this.

I suspect your best place to call drupal_set_content from is a hook_nodeapi(&amp;$node, "view")