According to Draconis, hyperlink color is something that's controlled by the interpreter, not the story file.
I have not tested this, but you could try releasing along with the Quixe interpreter (see §25.11. A playable web page in the manual):
Release along with an interpreter.
and editing the style.css file. From §25.13. Website templates:
We probably want to start from the "Standard" version of "style.css"
and edit in a few changes; the easiest way to get a clean copy of
"Standard"'s CSS file to work on is to release the project with a
"Standard" template, which causes this default "style.css" to appear
in the "Release" subfolder of the project's .materials folder. (But
it's wise to move the file out of "Release" before starting to edit it
- files in "Release" are overwritten by Inform whenever a release is made.)
Here's an example of setting hyperlink color in CSS:
http://www.w3schools.com/css/css_link.asp
If this works, then you could release your Quixe version, and that, at least, would have the font color you wanted.
Good luck!