Change color of navigation item in the list

I've done a search and I see how you would change the colors of all the categories links, but what I would like to do is change the colors of just two of the categories?

The links are currently blue, what I would like to do is make some of the ones red and bold.

This thread may be of help ...

http://www.zen-cart.com/showthread.php?153492-Changing-Font-Color-of-Single-Category-Link

I tried it, it didn't work

The referenced thread applies to the horizontal categories-tabs menu, not to the categories sidebox. The coding principles are relevant, but would have to be modified to fit.

You need to alter /includes/templates/your_template/sideboxes/tpl_categories.php (copy it from /template_default/sideboxes/). There are comments in the file for making a particular category "special" in styling. You can also install Categories Dressing, define a category group for the desired categories, and style the group. If that is the only thing you want to customize in the sidebox, it would probably be easier to do the manual edits according to the comment.